KR20240121577A - Method and apparatus for sending and receiving of encrypted message between devices - Google Patents

Abstract

In a wireless communication system, an electronic device transmitting a message obtains a first encrypted message in which a first message is encrypted based on a first session key, transmits the first encrypted message to a second electronic device, obtains a second session key based on the first message and the first session key, obtains a second encrypted message in which the second message is encrypted based on the second session key, and transmits the second encrypted message to the second electronic device.

Description

METHOD AND APPARATUS FOR SENDING AND RECEIVING OF ENCRYPTED MESSAGE BETWEEN DEVICES

The present invention relates to a method and device for transmitting and receiving encrypted messages between terminals.

SMS messages are widely used as one of the multi-factor authentication factors. Accordingly, SMS messages may be exposed to various security threats. Accordingly, in the case of message transmission services provided between a sending device and a receiving device in a general mobile communication network, provision of an encryption function may be required.

According to one embodiment of the present disclosure, a first electronic device for transmitting a message in a wireless communication system is provided. The first electronic device includes a transceiver and at least one processor connected to the transceiver. The at least one processor obtains a first encrypted message in which a first message is encrypted based on a first session key, transmits the first encrypted message to a second electronic device, obtains a second session key based on the first message and the first session key, obtains a second encrypted message in which the second message is encrypted based on the second session key, and transmits the second encrypted message to the second electronic device.

According to one embodiment of the present disclosure, a second electronic device for receiving a message in a wireless communication system is provided. The second electronic device includes a memory storing a session key, a transceiver; and at least one processor connected to the transceiver. The at least one processor receives a first encrypted message in which a first message is encrypted from a first electronic device, obtains a first decrypted message in which the first encrypted message is decrypted based on the stored session key, obtains a second session key based on the first decrypted message and the session key, receives a second encrypted message in which the second message is encrypted from the first electronic device, and obtains a second decrypted message in which the second encrypted message is decrypted based on the second session key.

According to one embodiment of the present disclosure, a method for transmitting a message in a wireless communication system is provided. The method includes: obtaining a first encrypted message in which a first message is encrypted based on a first session key; transmitting the first encrypted message to a second electronic device (1100); obtaining a second session key based on the first message and the first session key; obtaining a second encrypted message in which the second message is encrypted based on the second session key; and transmitting the second encrypted message to the second electronic device (1100).

According to one embodiment of the present disclosure, a method for a second electronic device to receive a message in a wireless communication system is provided. The method includes the steps of: receiving a first encrypted message in which a first message is encrypted from a first electronic device (1000); obtaining a first decrypted message in which the first encrypted message is decrypted based on a stored session key; obtaining a second session key based on the first decrypted message and the session key; receiving a second encrypted message in which the second message is encrypted from the first electronic device (1000); and obtaining a second decrypted message in which the second encrypted message is decrypted based on the second session key.

FIG. 1 is a diagram illustrating transmission and reception of an encrypted message according to one embodiment of the present disclosure.
FIG. 2 is a diagram for explaining a session key acquisition unit acquiring a session key according to one embodiment of the present disclosure.
FIG. 3 is a diagram illustrating a user code acquisition unit acquiring a user code according to an embodiment of the present disclosure.
FIG. 4 is a flowchart of a method for transmitting an encrypted message according to one embodiment of the present disclosure.
FIG. 5 is a flowchart of a method for obtaining a decrypted message according to an embodiment of the present disclosure.
FIG. 6 is a flowchart of a method for transmitting an encrypted message according to one embodiment of the present disclosure.
FIG. 7 is a flowchart of a method for obtaining a decrypted message according to one embodiment of the present disclosure.
FIG. 8 is a diagram illustrating an example of an electronic device performing communication according to one embodiment of the present disclosure.
FIG. 9 is a diagram illustrating an example of an electronic device performing communication according to one embodiment of the present disclosure.
FIG. 10 is a diagram illustrating an example of an electronic device performing communication according to an embodiment of the present disclosure.

In this disclosure, the expressions “at least one of a, b, or c” and “at least one of a, b and c” can refer to “a”, “b”, “c”, “a and b”, “a and c”, “b and c”, “all of a, b and c”, or variations thereof.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present disclosure. However, the present disclosure may be implemented in various different forms and is not limited to the embodiments described herein.

The terms used in this disclosure are described as currently used general terms in consideration of the functions mentioned in this disclosure, but these may mean various other terms depending on the intention of engineers engaged in the relevant field, precedents, the emergence of new technologies, etc. Therefore, the terms used in this disclosure should not be interpreted solely based on the names of the terms, but should be interpreted based on the meanings of the terms and the overall contents of this disclosure.

Additionally, the terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to limit the present disclosure.

Throughout the specification, when a part is said to be "connected" to another part, this includes not only the case where it is "directly connected" but also the case where it is "electrically connected" with another element in between.

As used herein, and particularly in the claims, the terms “said” and “above” and similar referents may refer to both the singular and the plural. In addition, unless there is a description that explicitly specifies the order of steps in describing a method according to the present disclosure, the described steps may be performed in any suitable order. The present disclosure is not limited by the order in which the described steps are described.

The appearances of the phrases “in some embodiments” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment.

Some embodiments of the present disclosure may be represented by functional block configurations and various processing steps. Some or all of these functional blocks may be implemented by various numbers of hardware and/or software configurations that perform specific functions. For example, the functional blocks of the present disclosure may be implemented by one or more microprocessors, or may be implemented by circuit configurations for a given function. Also, for example, the functional blocks of the present disclosure may be implemented by various programming or scripting languages. The functional blocks may be implemented by algorithms that are executed on one or more processors. In addition, the present disclosure may employ conventional techniques for electronic environment settings, signal processing, and/or data processing, etc. Terms such as “mechanism,” “element,” “means,” and “configuration” may be used broadly and are not limited to mechanical and physical configurations.

In addition, the connecting lines or connecting members between components depicted in the drawings are only illustrative of functional connections and/or physical or circuit connections. In an actual device, connections between components may be represented by various functional connections, physical connections, or circuit connections that may be replaced or added.

Additionally, terms such as "part", "module", etc. described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software, or a combination of hardware and software.

The term 'part' in the specification means a software or hardware component such as a Field Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC), and the 'part' performs certain roles. However, the 'part' is not limited to software or hardware. The 'part' may be configured to be on an addressable storage medium and may be configured to execute one or more processors. Thus, by way of example, the 'part' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functionality provided in the components and 'parts' may be combined into a smaller number of components and 'parts' or further separated into additional components and 'parts'. In addition, the components and '~parts' may be implemented to regenerate one or more CPUs within the device or secure multimedia card. Also, in an embodiment, the '~part' may include one or more processors.

Additionally, terms including ordinal numbers, such as “first” or “second,” used herein may be used to describe various components, but the components should not be limited by the terms. The terms may be used for the purpose of distinguishing one component from another.

For example, although the present specification describes a first electronic device and a second electronic device, this is only used to distinguish between different devices and should not be limited thereto.

For example, although the first comparison data and the second comparison data are described in this specification, they are only used to distinguish whether the comparison data is acquired from the first electronic device or the comparison data is acquired from the second electronic device, and thus should not be limited thereto.

For example, although the first session key, second session key, etc. are described in this specification, they are only used to distinguish between different session keys, and should not be limited thereto.

The first electronic device may be understood as a message transmission device and may include, for example, a server, a base station, or a terminal. The second electronic device may be understood as a message reception device and may include, for example, a server, a base station, or a terminal. Hereinafter, the base station is a subject that performs resource allocation of the terminal and may be at least one of a Node B, a BS (Base Station), an eNB (eNode B), a gNB (gNode B), or an xNode B (x is an alphabet including g and e), a wireless access unit, a base station controller, a satellite, an airborn, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a vehicular, a satellite, an airborn, a cellular phone, a smart phone, a computer, a laptop personal computer, a netbook computer, a digital camera, a navigation device, a wearable device, a smart watch, a home network system, a security system, a medical device, or a multimedia system capable of performing a communication function.

The advantages and features of the present disclosure, and the methods for achieving them, will become apparent by referring to the embodiments described in detail below together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below, but may be implemented in various different forms, and the embodiments are provided only to make the disclosure of the present disclosure complete and to fully inform a person having ordinary skill in the art to which the present disclosure belongs of the scope of the invention, and the present disclosure is defined only by the scope of the claims.

Hereinafter, the operating principle of a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. The same components shown in the drawings are indicated by the same reference numerals as much as possible even if they are shown in different drawings, and in the following description of the present invention, if it is determined that a specific description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the terms described below are terms defined in consideration of the functions in the present invention, and this may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout this specification.

In addition, the embodiments of the present disclosure may be applied to other communication systems having similar technical backgrounds or channel types to the embodiments of the present disclosure described below. In addition, the embodiments of the present disclosure may be applied to other communication systems through some modifications without significantly departing from the scope of the present disclosure as judged by a person having skilled technical knowledge.

SMS (short message service) is one of the user-friendly multi-factor authentication mechanisms. However, SMS messages may be exposed to security threats. For example, if leaked personal data of a user is used and a third party controls the user's mobile phone SIM (Subscriber Identify Module) card, a SIM swap may occur, and a third party may receive data such as messages and calls through a SIM swap.

Or, if a malicious program such as a Trojan is used on the receiving device, SMS messages may be transmitted or forwarded from the receiving device to a third party such as a hacker. If the network incorrectly forwards the message to a third party other than the intended recipient, the message may be exposed to a security threat. If the message is intercepted or eavesdropped, the message may also be exposed to a security threat.

In various embodiments of the present disclosure, the message may include an OTP (one-time password). For example, an SMS-based OTP may be used. The OTP may be used as a component of a multi-factor authentication scheme. The OTP may be used as a password that is valid for only one login session or transaction, and may enhance security compared to a static password-based authentication scheme. A service providing an OTP may require the user to register a phone number.

When a user logs into a web application or accesses a company's private network, an OTP may be required for user authentication. An OTP may be used for authorization. For example, an OTP may be used to authorize a particular request or transaction. For example, in an online banking web application, a user may be required to authenticate themselves by entering a valid username and password to initiate a transaction. Immediately after requesting a transaction, the user may receive an SMS message containing an OTP to authorize the transaction.

As mentioned above, the message can be exposed to security threats in various ways. Accordingly, the device can encrypt and transmit the message to enhance security. For example, when the service generates the message, the message can be encrypted with a user specific key. In this case, each user can have a unique secret key. The encrypted message can be transmitted from the service to the user's electronic device, such as a mobile phone. The user's device can decrypt the encrypted message and display the message.

When a symmetric key is used in OTP, it can be attacked using methods such as CPA (chosen plaintext attack) and KPA (known-plaintext attack). If the key is leaked, encrypted messages can be easily decrypted by a third party and the contents of the message can be exposed.

According to various embodiments of the present disclosure, even in the case where there is a security threat such as the above, the possibility of being exposed to a security threat can be reduced by encrypting with a new session key obtained based on the session key and message. In addition, when processing a request for a change or reissue of a SIM card, the session key is required for user identification, so that the security performance of the system can be enhanced.

According to various embodiments of the present disclosure, it can be identified whether the sender or receiver of a message or call corresponds to a registered user. According to various embodiments of the present disclosure, if the owner of the SIM card of the sender or receiver changes, the electronic device can provide a warning to the user to instruct the owner to change.

FIG. 1 is a diagram illustrating transmission and reception of an encrypted message according to one embodiment of the present disclosure.

Referring to FIG. 1, the first electronic device (1000) may be an electronic device capable of transmitting an encrypted message (130) in which a message (100) is encrypted. Referring to FIG. 1, the first electronic device (1000) may include a transceiver (1020), a processor (1010), and a memory (not shown). The components of the first electronic device (1000) are not limited to the examples described above.

The first electronic device (1000) may include more or fewer components than the components described above. In addition, the processor (1010), the transceiver (1020), and the memory (not shown) may be implemented in the form of a single chip. According to an example, the first electronic device (1000) may be implemented as various forms of electronic devices including a display.

The processor (1010) may control a series of processes so that the first electronic device (1000) may operate according to an embodiment of the present disclosure. For example, the processor (1010) may control a series of processes so that the first electronic device may obtain an encrypted message.

The processor (1010) may include at least one processor. For example, the processor (1010) may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper layers such as application programs. The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

The transceiver (1020) is a general term for the receiver of the first electronic device and the transmitter of the first electronic device, and can transmit and receive signals with other electronic devices. At this time, the transmitted and received signals can include control information and data. To this end, the transceiver (1020) can be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-down-converts a received signal.

However, this is only one embodiment of the transceiver (1020), and the components of the transceiver (1020) are not limited to an RF transmitter and an RF receiver. The transceiver (1020) may include wired and wireless transceivers, and may include various configurations for transmitting and receiving signals.

Additionally, the transceiver (1020) may receive a signal through a communication channel (e.g., a wireless channel) and output it to the processor (1010), and transmit the signal output from the processor (1010) through the communication channel. In one embodiment, the transceiver (1020) may transmit a message to the second electronic device (1120) through an MNO (Mobile Network Operator).

A memory (not shown) according to one embodiment can store at least one instruction. The memory (not shown) can store at least one program executed by the processor (1010). The memory (not shown) can store control information or data included in an acquired signal. In addition, the memory (not shown) can store data input to the first electronic device (1000) or output from the first electronic device (1000).

The memory (not shown) may include at least one type of storage medium or a combination of storage media among a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (e.g., SD or XD memory, etc.), a RAM (Random Access Memory), a SRAM (Static Random Access Memory), a ROM (Read-Only Memory), an EEPROM (Electrically Erasable Programmable Read-Only Memory), a PROM (Programmable Read-Only Memory), a magnetic memory, a magnetic disk, and an optical disk.

In one embodiment, a memory (not shown) of the first electronic device (1000) may store one or more instructions for transmitting an encrypted message.

In one embodiment, a memory (not shown) of the first electronic device (1000) may store one or more instructions for obtaining an encrypted message (130) in which a message (100) is encrypted based on a session key.

In one embodiment, a memory (not shown) of the first electronic device (1000) may store one or more instructions for transmitting an encrypted message (130) to the second electronic device (1100).

In one embodiment, a memory (not shown) of the first electronic device (1000) may store one or more instructions for obtaining a new session key based on the session key and message (100).

Referring to FIG. 1, the second electronic device (1100) may be an electronic device capable of receiving an encrypted message in which the message is encrypted. Referring to FIG. 1, the second electronic device (1100) may include a transceiver (1120), a processor (1110), and a memory (not shown). The components of the second electronic device (1100) are not limited to the examples described above.

The second electronic device (1100) may include more or fewer components than the components described above. In addition, the processor (1110), the transceiver (1120), and the memory (not shown) may be implemented in the form of a single chip. According to an example, the second electronic device (1100) may be implemented as various forms of electronic devices including a display.

The processor (1110) may control a series of processes so that the second electronic device (1100) may operate according to an embodiment of the present disclosure. For example, the processor (1110) may control a series of processes so that the second electronic device may obtain a decrypted message.

The processor (1110) may include at least one processor. For example, the processor (1110) may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls upper layers such as application programs. The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

The transceiver (1120) is a general term for the receiver of the second electronic device and the transmitter of the second electronic device, and can transmit and receive signals with another electronic device, such as the first electronic device. At this time, the transmitted and received signals can include control information and data. To this end, the transceiver (1120) can be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-down-converts a received signal.

However, this is only one embodiment of the transceiver (1120), and the components of the transceiver (1120) are not limited to an RF transmitter and an RF receiver. The transceiver (1120) may include wired and wireless transceivers, and may include various configurations for transmitting and receiving signals.

Additionally, the transceiver (1120) can receive a signal through a communication channel (e.g., a wireless channel) and output it to the processor (1110), and transmit a signal output from the processor (1110) through the communication channel.

A memory (not shown) according to one embodiment can store at least one instruction. The memory (not shown) can store at least one program executed by the processor (1110). The memory (not shown) can store control information or data included in an acquired signal. In addition, the memory (not shown) can store data input to or output from the second electronic device (1100).

The memory (not shown) may include at least one type of storage medium or a combination of storage media among a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (e.g., SD or XD memory, etc.), a RAM (Random Access Memory), a SRAM (Static Random Access Memory), a ROM (Read-Only Memory), an EEPROM (Electrically Erasable Programmable Read-Only Memory), a PROM (Programmable Read-Only Memory), a magnetic memory, a magnetic disk, and an optical disk.

In one embodiment, a memory (not shown) of the second electronic device (1100) may store one or more instructions for receiving an encrypted message (130) from the first electronic device (1000).

In one embodiment, a memory (not shown) of the second electronic device (1100) may store one or more instructions for obtaining an encrypted message (130) in which a message (100) is encrypted based on a session key.

In one embodiment, a memory (not shown) of the second electronic device (1100) may store one or more instructions for obtaining a decrypted message (150) in which an encrypted message (130) is decrypted based on a session key.

In one embodiment, a memory (not shown) of the second electronic device (1100) may store one or more instructions for obtaining a new session key based on the session key and the message.

FIG. 2 is a diagram for explaining a session key acquisition unit acquiring a session key according to one embodiment of the present disclosure.

In one embodiment, the processor (1010) of the first electronic device (1000) and the processor (1110) of the second electronic device (1100) may include a session key acquisition unit (250).

In one embodiment, the session key acquisition unit (250) can generate the first session key (201). For example, the session key acquisition unit (250) can acquire the first session key (201) based on at least one of a random key generation method, a key derivation method, a key exchange method, or a hybrid key generation method. For example, the session key acquisition unit (250) can generate the first session key (201) based on a random key generation method.

In one embodiment, the session key acquisition unit (250) may generate a second session key (301) based on the first session key (201) and the message (100). For example, the session key acquisition unit (250) may input the message and the stored session key into a hash function to acquire the second session key (203).

A hash function can be used to map data of arbitrary size to a value of fixed size. The value returned by a hash function can be expressed as a hash value, hash code, digest, or hash. The process of mapping or inputting a hash function to obtain a hash value can be called hashing.

If even a part of the input value of the hash function is different, a completely different hash value may be output. Accordingly, if at least a part of the session key or message input to the hash function is different, a completely different session key may be generated. The first electronic device and the second electronic device can improve the security performance when performing communication by using the session key and the message together as inputs to the hash function.

In one embodiment, if there is a first session key (201) and a decryption message (150), the session key acquisition unit (250) can generate a second session key (301) based on the first session key (201) and the decryption message (150). For example, the session key acquisition unit (250) can input the message and the stored session key into a hash function to acquire the second session key (203).

FIG. 3 is a diagram illustrating a user code acquisition unit acquiring a user code according to an embodiment of the present disclosure.

In one embodiment, the processor (1010) of the first electronic device (1000) may include a user code acquisition unit (350). In one embodiment, the second electronic device (1100) may perform a registration procedure on the first electronic device. The first electronic device (1000) may acquire registration information (301) provided by the second electronic device (1100).

In one embodiment, the user code acquisition unit (350) can acquire a user code (303) based on the registration information (301). For example, the user code acquisition unit (350) can acquire a user code (303) by inputting the registration information (301) into a hash function.

In one embodiment, the registration information (301) may include at least one of name information, address information, date of birth or date of birth information, or a random code. In one embodiment, the user code may be unique to each user and may be associated with the caller's phone number. The user code (303) may be mapped to a session key or a user name. For example, it may form an ordered pair such as (user code, session key).

In one embodiment, the first electronic device can transmit at least one of a user code, a user name, or a first session key to the second electronic device. For example, the first electronic device can transmit a sequence pair composed as (session key, user code, user name) to the second electronic device.

In one embodiment, the transmitted user code, user name, and session key may be stored in the second electronic device. When the first encrypted message is transmitted to the second electronic device, the first encrypted message may be decrypted or the first electronic device may be authorized based on the user code, user name, or first session key.

For example, the second electronic device can obtain a session key or user name mapped to the user code using the user code. The second electronic device can perform decryption on the first encrypted message based on the obtained session key.

In one embodiment, the first electronic device (1000) and the second electronic device (1100) can obtain comparison data in which the user code is encrypted based on the session key. For example, the first electronic device can obtain first comparison data in which the user code is encrypted based on the session key.

In one embodiment, when a first electronic device (1000) transmits a SIP (Session Initiation Protocol) invite message to a second electronic device (1100), the SIP (Session Initiation Protocol) invite message may include a user code and first compare data. For example, the SIP invite message may be transmitted including a user code and first compare data as shown in the following [Table 1].

SIP INVITE
INVITE sip:+14155552222@example.pstn.twilio.com SIP/2.0 Via: SIP/2.0/UDP 192.168.10.10:5060;branch=z9hG4bK776asdhds Max-Forwards: 70
To: "Bob"<sip:+14155552222@example.pstn.twilio.com> From: "Alice"<sip:+14155551111@example.pstn.twilio.com>;tag=1
Call-ID: a84b4c76e66710
CSeq: 1 INVITE Contact: "Alice"<sip:+14155551111@192.168.10.10:5060> Diversion: "Sales"<sip:+14155550000@example.pstn.twilio.com>
P-Asserted-Identity: "Alice"<sip:+14155551111@example.pstn.twilio.com>
Call-info: call-reason=<sender user code><sender compare data>

FIG. 4 is a flowchart of a method for transmitting an encrypted message according to an embodiment of the present disclosure. In step S410, a first electronic device obtains a first encrypted message in which the first message is encrypted based on a first session key.

In one embodiment, the first electronic device can obtain a first session key. For example, the first electronic device can generate the first session key. For example, the first electronic device can generate the first session key based on at least one of a random key generation method, a key derivation method, a key exchange method, or a hybrid key generation method.

For example, the first electronic device can generate the first session key based on the stored session key and the message. For example, the first electronic device can generate the first session key based on the stored 0th session key and the 0th message. For example, the first electronic device can generate the first session key by hashing the message and the stored session key.

In one embodiment, the first electronic device can transmit at least one of the 0 session key or the first session key to the second electronic device based on a secure key exchange method. For example, the first electronic device can transmit the first session key based on an asymmetric key exchange method. The transmitted first session key can be stored in the second electronic device.

In one embodiment, a first electronic device can obtain a first message. For example, the first electronic device can receive, input, or generate the first message. The first electronic device can encrypt the first message using a first session key to obtain an encrypted first encrypted message.

In step S420, the first electronic device transmits a first encrypted message to the second electronic device (1100).

In one embodiment, the first electronic device can send a Session Initiation Protocol invite (SIP invite) message to the second electronic device. For example, the first electronic device can attempt to contact or call the second electronic device based on the SIP invite message. In one embodiment, the first encrypted message can include the SIP invite message. In one embodiment, the first electronic device can send the SIP invite message instead of the first encrypted message.

In step S430, the first electronic device obtains a second session key based on the first message and the first session key.

In one embodiment, the first electronic device can input the first message and the first session key into a hash function to obtain the second session key. For example, the first message and the first session key can be input into a hash function to output the second session key.

In one embodiment, the first electronic device can identify whether the first session key of the second electronic device and the first session key of the first electronic device are synchronized.

In one embodiment, when a success delivery report of the first message is received, the first electronic device may identify that the first session key is synchronized with the second electronic device. For example, when the second electronic device receives and decrypts the first encrypted message, the success delivery report may be received from a short message service center (SMCS).

In one embodiment, when the first session key is synchronized between the first electronic device and the second electronic device, the first electronic device can update the first session key based on the second session key. For example, the first electronic device can replace the first session key with the second session key. The first electronic device can perform communication using the second session key.

In one embodiment, if the first session key of the first electronic device is not synchronized with the first session key of the second electronic device, the first electronic device can perform communication using the first session key. For example, the first electronic device can transmit a second message encrypted based on the first session key, or can retransmit the first encrypted message.

Referring to FIG. 4, steps S420 and S430 are illustrated as being performed first, and then step S440 is performed. However, in one embodiment, steps S420, S430, and S440 may be performed simultaneously, and step S440 may be performed first, and then at least one of steps S420 or S430 may be performed first.

In step S440, the first electronic device obtains a second encrypted message in which the second message is encrypted based on the second session key.

In one embodiment, if the first session key of the first electronic device is synchronized with the session key of the second electronic device, the first electronic device can obtain a second encrypted message in which the second message is encrypted based on the second session key.

In step S450, the first electronic device transmits a second encrypted message to the second electronic device.

In one embodiment, the first electronic device can obtain a third session key based on the second message and the second session key. For example, the second message and the second session key can be input into a hash function to output the third session key.

In one embodiment, the first electronic device can identify whether the second session key of the second electronic device is synchronized with the session key of the first electronic device.

In one embodiment, when a success delivery report of the second message is received, the first electronic device may identify that the second session key is synchronized with the second electronic device. For example, when the second electronic device receives and decrypts the second encrypted message, the success delivery report may be received from a short message service center (SMCS).

In one embodiment, if the second session key is synchronized between the first electronic device and the second electronic device, the first electronic device can update the second session key based on the third session key. For example, the first electronic device can replace the second session key with the third session key. The first electronic device can perform communication using the third session key. The first electronic device can obtain a third encrypted message in which the third message is encrypted based on the third session key. If the session key is invalid, decryption of the encrypted message can fail.

In one embodiment, if the second session key of the first electronic device is not synchronized with the second session key of the second electronic device, the first electronic device can perform communication using the second session key. For example, the first electronic device can transmit a third message encrypted based on the second session key, or can retransmit the second encrypted message.

In one embodiment, the first electronic device can send a Session Initiation Protocol invite (SIP invite) message to the second electronic device. For example, the first electronic device can attempt to contact or call the second electronic device based on the SIP invite message. In one embodiment, the second encrypted message can include the SIP invite message. In one embodiment, the first electronic device can send the SIP invite message instead of the second encrypted message.

In one embodiment, at least one of steps S410 to S450 may be omitted or performed through another device, such as a separate server, system, etc.

FIG. 5 is a flowchart of a method for obtaining a decrypted message according to an embodiment of the present disclosure.

In step S510, the second electronic device receives a first encrypted message in which the first message is encrypted from the first electronic device (1000).

In one embodiment, the second electronic device can receive a session key from the first electronic device. At least one of the 0 session key or the first session key can be generated based on a random key generation method, and the session key can include at least one of the 0 session key or the first session key. The second electronic device can store the received session key.

In one embodiment, the second electronic device can receive the session key from the first electronic device based on a secure key exchange method. For example, the second electronic device can receive the first session key based on an asymmetric key exchange method. The received first session key can be stored in the second electronic device. The stored session key can be used to decrypt a first encrypted message that is subsequently received.

In one embodiment, the second electronic device can receive a Session Initiation Protocol invite (SIP invite) message from the first electronic device. The second electronic device can attempt to contact or call the second electronic device based on the SIP invite message. In one embodiment, the first encrypted message can include the SIP invite message. In one embodiment, the second electronic device can receive the SIP invite message instead of the first encrypted message.

In step S520, the second electronic device obtains a first decrypted message in which the first encrypted message is decrypted based on the stored session key.

In one embodiment, if the first comparison data and the second comparison data match, the second electronic device can obtain the first decrypted message based on the stored session key. In one embodiment, if the first decrypted message is obtained and the sender number of the first decrypted message is an unregistered number, the second electronic device can map the sender number of the first decrypted message to the name of the contact.

In one embodiment, if the first decryption message fails to be obtained, the second electronic device may manage the sender number of the first encrypted message as an unsafe number. For example, the second electronic device may include the sender number of the first encrypted message in a list of unsafe numbers.

In one embodiment, when the second electronic device receives a SIP invite message, the second electronic device may include the calling number in a list of unsafe numbers. For example, the second electronic device may notify the user of the second electronic device that the user is unknown and may ask the user of the second electronic device whether to continue the call. If it is determined not to continue the call, the second electronic device may cancel the call.

In step S530, the second electronic device obtains a second session key based on the first decryption message and the session key.

In one embodiment, the first electronic device may input the first decrypted message and the session key into a hash function to obtain the second session key. For example, the first decrypted message and the session key mapped to the received user code may be input into the hash function to output the second session key. The obtained second session key may be stored.

In one embodiment, the second electronic device can identify whether the first session key of the first electronic device and the session key of the second electronic device are synchronized. For example, if the second electronic device receives the first encrypted message and successfully decrypts the first encrypted message, the second electronic device can identify that the first session key and the first electronic device are synchronized.

If the first encrypted message fails to be received or the first encrypted message is not decrypted, the second electronic device can identify that the first electronic device and the first session key are not synchronized.

In one embodiment, if the first session key is synchronized between the first electronic device and the second electronic device, the second electronic device can update the first session key based on the second session key. For example, the second electronic device can replace the first session key with the second session key. The second electronic device can perform communication using the second session key.

In one embodiment, if the first session key of the first electronic device is not synchronized with the session key of the second electronic device, the second electronic device can perform communication using the first session key. For example, the second electronic device can request the first electronic device to retransmit the message, or can notify that the message delivery failed. The second electronic device can decrypt the retransmitted encrypted message based on the first session key.

In step S540, the second electronic device receives a second encrypted message in which the second message is encrypted from the first electronic device (1000).

In one embodiment, the second electronic device may receive a Session Initiation Protocol invite (SIP invite) message from the first electronic device. For example, the second electronic device may attempt to contact or call the second electronic device based on the SIP invite message. In one embodiment, the second encrypted message may include the SIP invite message. In one embodiment, the second electronic device may receive the SIP invite message instead of the second encrypted message.

In step S550, the second electronic device obtains a second decrypted message in which the second encrypted message is decrypted based on the second session key.

In one embodiment, the second electronic device may display the acquired second decryption message. If decryption fails based on the second session key, the second electronic device may determine that there is no valid session key.

In one embodiment, when a second decrypted message is obtained and the sender number of the second decrypted message is an unregistered number, the second electronic device can map the sender number of the second decrypted message to a name of a contact. Even if it is sent to a number different from the number in the contact, the user of the second electronic device can determine that it corresponds to a name of an existing contact.

In one embodiment, if decryption fails based on the stored session key, the second electronic device can manage the second encrypted message as an unsecure number. For example, the second electronic device can include the sender number of the second encrypted message in a list of unsecure numbers. For example, the second electronic device can notify the user of the second electronic device that the user is unknown.

For another example, if the second electronic device receives a SIP invite message, the second electronic device may include the calling number in a list of unsafe numbers. For example, the second electronic device may notify the user of the second electronic device that the caller is unknown and ask the user of the second electronic device whether to continue the call.

In one embodiment, the second electronic device can obtain the third session key based on the second decryption message and the second session key. For example, the second decryption message and the session key mapped to the received user code can be input into a hash function to output the third session key.

In one embodiment, the second electronic device can identify whether the second session key of the first electronic device and the second session key of the second electronic device are synchronized. For example, if the second electronic device receives the second encrypted message and successfully decrypts the second encrypted message, the second electronic device can identify that the second session key of the first electronic device is synchronized. If the first encrypted message fails to be received or the second encrypted message is not decrypted, the second electronic device can identify that the second session key of the first electronic device is not synchronized.

In one embodiment, if the second session key is synchronized between the first electronic device and the second electronic device, the second electronic device can update the second session key based on the third session key. For example, the second electronic device can replace the second session key with the third session key. The second electronic device can perform communication using the third session key.

In one embodiment, if the second session key of the first electronic device is not synchronized with the second session key of the second electronic device, the second electronic device can perform communication using the second session key. For example, the second electronic device can request the first electronic device to retransmit the message or notify that the message delivery failed. The second electronic device can decrypt the retransmitted encrypted message based on the second session key.

In one embodiment, the second electronic device can receive a third decryption message. In one embodiment, the second electronic device can obtain a third decryption message in which the third encrypted message is decrypted based on the third session key.

Step S520 may correspond to step S550, and some overlapping parts may be omitted. In one embodiment, at least one of steps S510 to S550 may be omitted or performed through another device, such as a separate server, system, etc.

The first comparison data and the user code may be used by both the first electronic device and the second electronic device to determine whether the session key is valid. If the session key is invalid, the second electronic device may fail to decrypt the encrypted message.

FIG. 6 is a flowchart of a method for transmitting an encrypted message according to one embodiment of the present disclosure.

In step S610, the first electronic device obtains a first encrypted message in which the first message is encrypted based on the first session key.

In one embodiment, a first electronic device can generate a first session key. For example, the first electronic device can generate the first session key. For example, the first electronic device can obtain the first session key based on at least one of a random key generation method, a key derivation method, a key exchange method, or a hybrid key generation method.

For example, the first electronic device can generate the first session key based on the stored session key and the message. For example, the first electronic device can generate the first session key based on the stored 0th session key and the 0th message. For example, the first electronic device can input the message and the stored session key into a hash function to obtain the first session key.

In one embodiment, the first electronic device can transmit at least one of the 0 session key or the first session key to the second electronic device based on a secure key exchange method. For example, the first electronic device can transmit the first session key based on an asymmetric key exchange method. The transmitted first session key can be stored in the second electronic device.

In one embodiment, a first electronic device can obtain a first message. For example, the first electronic device can receive, input, or generate the first message. The first electronic device can obtain a first encrypted message in which the first message is encrypted using a first session key.

In step S620, the first electronic device generates first comparison data in which the user code is encrypted based on the first session key.

In one embodiment, when the second electronic device registers with the first electronic device based on the phone number of the second electronic device, the first electronic device may generate at least one of a user code or a user name based on the registration information of the second electronic device.

In one embodiment, the first electronic device may input registration information into a hash function to obtain a user code. The user code is associated with a user of the first electronic device, i.e., the caller. The user name may include the name of the caller.

In one embodiment, the registration information may include at least one of name information, address information, date of birth or date of birth information, or a random code. The user code may be mapped to a session key or a user name. The user code may be used as identification information for the user. The user code may be unique to each user and may be associated with the caller's phone number.

In one embodiment, the first electronic device can transmit at least one of a user code, a user name, or a first session key to the second electronic device. For example, the first electronic device can transmit a sequence pair composed as (session key, user code, user name) to the second electronic device.

In one embodiment, at least one of the transmitted user code, user name, or first session key may be stored in the second electronic device. When the first encrypted message is transmitted to the second electronic device, the first encrypted message may be decrypted or the first electronic device may be authorized based on the user code, user name, or first session key.

For example, the second electronic device can obtain a session key or user name mapped to the user code using the user code. The second electronic device can perform decryption on the first encrypted message based on the obtained session key.

In one embodiment, the first electronic device can generate first comparison data having an encrypted user code based on the first session key.

Referring to FIG. 6, step S610 is illustrated as being performed first and then step S620, but in one embodiment, steps S610 and S620 may be performed simultaneously, or step S620 may be performed first and then step S610 may be performed. For example, the first electronic device may generate first comparison data based on the acquired first session key, and obtain a first encrypted message based on the first session key.

In step S630, the first electronic device transmits a first encrypted message to the second electronic device (1100).

In one embodiment, the first electronic device can send a Session Initiation Protocol invite (SIP invite) message to the second electronic device. For example, the first electronic device can attempt to contact or call the second electronic device based on the SIP invite message. In one embodiment, the first encrypted message can include the SIP invite message. In one embodiment, the first electronic device can send the SIP invite message instead of the first encrypted message.

In step S640, the first electronic device transmits first comparison data and a user code to the second electronic device (1100).

Referring to FIG. 6, step S630 is illustrated as being performed first and then step S640, but in one embodiment, steps S630 and S640 may be performed simultaneously, and step S640 may be performed first and then step S630 may be performed.

For example, the first electronic device may transmit the first comparison data and the user code to the second electronic device along with the first encrypted message. As another example, the first electronic device may first transmit at least one of the first comparison data or the user code, and then transmit the first encrypted message to the second electronic device.

For example, the first electronic device may transmit the first comparison data and the user code to the second electronic device along with the SIP invite message. As another example, the first electronic device may first transmit at least one of the first comparison data or the user code, and then transmit the SIP invite message to the second electronic device.

In step S650, the first electronic device obtains a second session key based on the first message and the first session key.

In one embodiment, the first electronic device can input the first message and the first session key into a hash function to obtain the second session key. For example, the first message and the first session key can be input into a hash function to output the second session key.

In one embodiment, the first electronic device can identify whether the session key of the second electronic device and the first session key of the first electronic device are synchronized.

In one embodiment, when a success delivery report of the first message is received, the first electronic device may identify that the first session key is synchronized with the second electronic device. For example, when the second electronic device receives and decrypts the first encrypted message, the success delivery report may be received from a short message service center (SMCS).

In one embodiment, when the first session key is synchronized between the first electronic device and the second electronic device, the first electronic device can update the first session key based on the second session key. For example, the first electronic device can replace the first session key with the second session key. The first electronic device can perform communication using the second session key.

In one embodiment, if the first session key of the first electronic device is not synchronized with the session key of the second electronic device, the first electronic device can perform communication using the first session key. For example, the first electronic device can transmit a second message encrypted based on the first session key, or can retransmit the first encrypted message.

In step S660, the first electronic device obtains a second encrypted message in which the second message is encrypted based on the second session key.

In one embodiment, when the first session key is synchronized with the second electronic device, the first electronic device can obtain a second encrypted message in which the second message is encrypted based on the second session key.

In step S670, the first electronic device transmits a second encrypted message to the second electronic device.

In one embodiment, the first electronic device can obtain a third session key based on the second message and the second session key. For example, the second message and the second session key can be input into a hash function to output the third session key.

In one embodiment, the first electronic device can identify whether a session key of the first electronic device and a second session key of the second electronic device are synchronized.

In one embodiment, when a success delivery report of the second message is received, the first electronic device may identify that the second session key is synchronized with the second electronic device. For example, when the second electronic device receives and decrypts the second encrypted message, the success delivery report may be received from a short message service center (SMCS).

In one embodiment, when the second session key is synchronized between the first electronic device and the second electronic device, the first electronic device can update the second session key based on the third session key. For example, the first electronic device can replace the second session key with the third session key. The first electronic device can perform communication using the third session key. The first electronic device can obtain a third encrypted message in which the third message is encrypted based on the third session key.

In one embodiment, if the second session key of the first electronic device is not synchronized with the second session key of the second electronic device, the first electronic device can perform communication using the second session key. For example, the first electronic device can transmit a third message encrypted based on the second session key, or can retransmit the second encrypted message.

In one embodiment, the first electronic device generates first comparison data encrypted with a user code based on the second session key. The content of generating the first comparison data may correspond to step S620. In one embodiment, the first electronic device transmits, to the second electronic device, first comparison data encrypted based on the second session key and a user code. The content of transmitting the first comparison data and the user code may correspond to step S640.

The first comparison data and the user code may be used by both the first electronic device and the second electronic device to determine whether the session key is valid. If the session key is invalid, decryption of the encrypted message may fail.

In one embodiment, the first electronic device can send a Session Initiation Protocol invite (SIP invite) message to the second electronic device. For example, the first electronic device can attempt to contact or call the second electronic device based on the SIP invite message. In one embodiment, the second encrypted message can include the SIP invite message. In one embodiment, the first electronic device can send the SIP invite message instead of the second encrypted message.

For example, the first electronic device may transmit the first comparison data and the user code to the second electronic device along with the SIP invite message. As another example, the first electronic device may first transmit at least one of the first comparison data or the user code, and then transmit the SIP invite message to the second electronic device.

In one embodiment, at least one of steps S610 to S670 may be omitted or performed through another device, such as a separate server, system, etc.

FIG. 7 is a flowchart of a method for obtaining a decrypted message according to one embodiment of the present disclosure.

In step S710, the second electronic device receives a first encrypted message in which the first message is encrypted from the first electronic device (1000).

In one embodiment, the second electronic device may perform a registration procedure on the first electronic device based on registration information of the second electronic device. The registration information may include at least one of name information, address information, date of birth information, or a random code.

In one embodiment, the second electronic device can receive at least one of a first session key, a user code, or a user name from the first electronic device. For example, the second electronic device can receive a sequence pair configured as (session key, user code, user name) from the first electronic device. The user code can be mapped to at least one of the session key or the user name. In one embodiment, the second electronic device can store the first session key.

In one embodiment, the second electronic device can receive the session key from the first electronic device based on a secure key exchange method. For example, the second electronic device can receive the first session key based on an asymmetric key exchange method. The received first session key can be stored in the second electronic device. The stored session key can include the first session key. The stored session key can be used to decrypt a first encrypted message that is subsequently received.

In one embodiment, the second electronic device can receive a Session Initiation Protocol invite (SIP invite) message from the first electronic device. The second electronic device can attempt to contact or call the second electronic device based on the SIP invite message. In one embodiment, the first encrypted message can include the SIP invite message. In one embodiment, the second electronic device can receive the SIP invite message instead of the first encrypted message.

In step S720, the second electronic device receives a user code and first comparison data from the first electronic device (1000).

Referring to FIG. 7, step S710 is illustrated as being performed first and then step S720, but in one embodiment, steps S710 and S720 may be performed simultaneously, and step S720 may be performed first and then step S710 may be performed.

For example, the second electronic device may receive the first comparison data and the user code from the first electronic device along with the first encrypted message. As another example, the second electronic device may first receive at least one of the first comparison data or the user code, and then receive the first encrypted message from the first electronic device.

For example, the second electronic device may receive the first comparison data and the user code from the first electronic device along with the SIP invite message. As another example, the second electronic device may first receive at least one of the first comparison data or the user code, and then receive the SIP invite message from the first electronic device.

In step S730, if the session key is mapped to the user code, the second electronic device can obtain second comparison data in which the user code is encrypted based on the session key.

In one embodiment, the second electronic device can identify whether the stored session key is mapped to the user code. The second electronic device can obtain a session key mapped to the user code among the stored session keys. If there is a session key mapped to the user code, the second electronic device can determine that there is a valid session key. If the session key mapped to the user code cannot be found among the stored session keys, the second electronic device can determine that there is no valid session key.

In one embodiment, the second electronic device can obtain the second comparison data by encrypting the received user code based on the stored session key. For example, the second electronic device can obtain the second comparison data by encrypting the received user code based on the session key mapped to the received user code.

In step S740, the second electronic device obtains a first decrypted message in which the first encrypted message is decrypted based on the session key.

In one embodiment, if the first comparison data and the second comparison data match, the second electronic device can obtain the first decryption message based on the stored session key. For example, if the first comparison data and the second comparison data are identical, the second electronic device can identify that the first comparison data and the second comparison data match.

In one embodiment, when a first decrypted message is obtained and the sender number of the first decrypted message is an unregistered number, the second electronic device can map the sender number of the first decrypted message to the name of the contact. For example, the second electronic device can obtain user name information based on the received user code, and map the sender number of the first decrypted message to the name of the contact.

In one embodiment, if the session key is not mapped to the user code or if the first comparison data and the second comparison data do not match, the second electronic device may manage the sending number of the first encrypted message as an unsecure number. For example, the second electronic device may include the sending number of the first encrypted message in a list of unsecure numbers.

For another example, if the second electronic device receives a SIP invite message, the second electronic device may include the calling number in a list of unsafe numbers. For example, the second electronic device may notify the user of the second electronic device that the caller is an unknown user and may ask the user of the second electronic device whether to continue the call. If the decision is not to continue the call, the second electronic device may cancel the call.

In step S750, the second electronic device obtains a second session key based on the first decryption message and the session key.

In one embodiment, the first electronic device may input the first decrypted message and the session key into a hash function to obtain the second session key. For example, the first decrypted message and the session key mapped to the received user code may be input into the hash function to output the second session key. The obtained second session key may be stored.

In one embodiment, the second electronic device can identify whether the first session key of the first electronic device and the first session key of the second electronic device are synchronized. For example, if the second electronic device receives the first encrypted message and successfully decrypts the first encrypted message, the second electronic device can identify that the first electronic device and the first session key are synchronized.

If the first encrypted message fails to be received or the first encrypted message is not decrypted, the second electronic device may identify that the first session key of the first electronic device and the session key of the second electronic device are not synchronized.

In one embodiment, if the first session key is synchronized between the first electronic device and the second electronic device, the second electronic device can update the first session key based on the second session key. For example, the second electronic device can replace the first session key with the second session key. The second electronic device can perform communication using the second session key.

In one embodiment, if the first session key of the first electronic device is not synchronized with the session key of the second electronic device, the second electronic device can perform communication using the first session key. For example, the second electronic device can request the first electronic device to retransmit the message, or can notify that the message delivery failed. The second electronic device can decrypt the retransmitted encrypted message based on the first session key.

In step S760, the second electronic device receives a second encrypted message in which the second message is encrypted from the first electronic device (1000).

In one embodiment, the second electronic device may receive a Session Initiation Protocol invite (SIP invite) message from the first electronic device. For example, the second electronic device may attempt to contact or call the second electronic device based on the SIP invite message. In one embodiment, the second encrypted message may include the SIP invite message. In one embodiment, the second electronic device may receive the SIP invite message instead of the second encrypted message.

In step S770, the second electronic device obtains a second decrypted message in which the second encrypted message is decrypted based on the second session key.

In one embodiment, the second electronic device can display the acquired second decrypted message.

In one embodiment, the second electronic device can receive encrypted first comparison data based on the user code and the second session key from the first electronic device. For example, the second electronic device can receive the first comparison data and the user code from the first electronic device along with the second encrypted message.

For another example, the second electronic device may first receive at least one of the first comparison data or the user code, and then receive the second encrypted message from the first electronic device. For another example, the second electronic device may first receive the second encrypted message, and then receive at least one of the first comparison data or the user code from the first electronic device.

In one embodiment, the second electronic device can identify whether a stored session key is mapped to a user code. The second electronic device can obtain a session key that is mapped to a user code among the stored session keys.

If there is a session key mapped to the user code, the second electronic device can determine that there is a valid session key. If the session key mapped to the user code cannot be found among the stored session keys, the second electronic device can determine that there is no valid session key.

In one embodiment, the second electronic device can obtain the second comparison data by encrypting the received user code based on the stored session key. For example, the second electronic device can obtain the second comparison data by encrypting the received user code based on the session key mapped to the received user code.

In one embodiment, when a second decrypted message is obtained and the sender number of the second decrypted message is an unregistered number, the second electronic device can map the sender number of the second decrypted message to a name of a contact. Even if it is sent to a number different from the number in the contact, the user of the second electronic device can determine that it corresponds to a name of an existing contact.

In one embodiment, if the session key is not mapped to a user code or if the first comparison data and the second comparison data do not match, the second electronic device may manage the second encrypted message as an insecure number.

In one embodiment, the second electronic device can identify the user of the first electronic device. For example, the second electronic device can include the sender number of the second encrypted message in a list of unsafe numbers. For example, the second electronic device can notify the user of the second electronic device that the user is unknown. For example, if the owner of the SIM card changes to an unknown user, a warning pop-up can be provided to notify the user of the change of owner.

For another example, if the second electronic device receives a SIP invite message, the second electronic device may include the calling number in a list of unsafe numbers. For example, the second electronic device may notify the user of the second electronic device that the caller is unknown and ask the user of the second electronic device whether to continue the call.

In one embodiment, the second electronic device can obtain the third session key based on the second decryption message and the second session key. For example, the second decryption message and the session key mapped to the received user code can be input into a hash function to output the third session key.

In one embodiment, the second electronic device can identify whether the second session key of the first electronic device and the second session key of the second electronic device are synchronized. For example, if the second electronic device receives the second encrypted message and successfully decrypts the second encrypted message, the second electronic device can identify that the second session key of the first electronic device is synchronized. If the first encrypted message fails to be received or the second encrypted message is not decrypted, the second electronic device can identify that the second session key of the first electronic device is not synchronized.

In one embodiment, if the second session key is synchronized between the first electronic device and the second electronic device, the second electronic device can update the second session key based on the third session key. For example, the second electronic device can replace the second session key with the third session key. The second electronic device can perform communication using the third session key.

In one embodiment, if the second session key of the first electronic device is not synchronized with the second session key of the second electronic device, the second electronic device can perform communication using the second session key. For example, the second electronic device can request the first electronic device to retransmit the message or notify that the message delivery failed. The second electronic device can decrypt the retransmitted encrypted message based on the second session key.

In one embodiment, the second electronic device can receive a third decryption message. In one embodiment, the second electronic device can obtain a third decryption message in which the third encrypted message is decrypted based on the third session key.

Step S770 may correspond to step S740, and some overlapping parts may be omitted. In one embodiment, at least one of steps S710 to S770 may be omitted or performed through another device, such as a separate server, system, etc.

The first comparison data and the user code may be used by both the first electronic device and the second electronic device to determine whether the session key is valid. If the session key is invalid, the second electronic device may fail to decrypt the encrypted message.

FIG. 8 is a diagram illustrating an example of an electronic device performing communication according to one embodiment of the present disclosure.

The first electronic device (1000) can transmit a message to the second electronic device (1100) via the MNO (1200). There may be cases where the message is incorrectly transmitted from the first electronic device (1000) to the third electronic device (1300).

For example, if a user of a third electronic device (1300) obtains personal information about a user of a second electronic device (1100), a SIM swap attack may occur.

In cases such as when a SIM swap occurs, a third electronic device (1300), not a second electronic device (1100), can receive data such as messages and phone calls from the first electronic device (1000). If the message is not encrypted, the third electronic device (1300) can easily read the contents of the message.

According to one embodiment of the present disclosure, a first electronic device (1000) can transmit an encrypted message to a second electronic device (1100) through an MNO (1200). Even if the encrypted message is incorrectly transmitted from the first electronic device (1000) to the third electronic device (1300), the third electronic device (1300) may fail to decrypt the encrypted message because it does not have a session key for decryption, and may not be able to read the contents of the message. According to one embodiment of the present disclosure, when the owner of a SIM card changes, the first electronic device (1000) can transmit information notifying the user of the first electronic device (1000) of the owner change.

FIG. 9 is a diagram illustrating an example of an electronic device performing communication according to one embodiment of the present disclosure.

A first electronic device (1000) can transmit a message to a second electronic device (1100) via an MNO (1200). There may be a case where a message is forwarded from the second electronic device (1100) to a third electronic device (1300).

For example, when a second electronic device (1100) receives a message, malware, such as a Trojan horse, may be used to transmit the message from the second electronic device (1100) to the third electronic device (1300). The malware may receive, modify, delete, or transmit the message even without user intervention.

The third electronic device (1300) can receive data such as messages and phone calls from the second electronic device (1100). If the message is not encrypted, the third electronic device (1300) can easily read the contents of the message.

According to one embodiment of the present disclosure, a first electronic device (1000) can transmit an encrypted message to a second electronic device (1100) through an MNO (1200). Even when the encrypted message is transmitted from the second electronic device (1100) to a third electronic device (1300), the third electronic device (1300) may fail to decrypt the encrypted message because it does not have a session key for decryption, and may not be able to read the contents of the message.

FIG. 10 is a diagram illustrating an example of an electronic device performing communication according to an embodiment of the present disclosure.

There may be a case where a message is transmitted from a first electronic device (1000) to a third electronic device (1300). For example, a user of the third electronic device (1300) may deceive a user of the second electronic device (1100) and cause the second electronic device (1100) to request the MNO (1200) to transmit a message or call transmitted to the second electronic device (1100) to the third electronic device (1300).

When the first electronic device (1000) wants to transmit a message to the second electronic device (1100), the MNO (1200) can transmit the message to the third electronic device (1300). The third electronic device (1300) can receive data such as messages and phone calls. If the message is not encrypted, the third electronic device (1300) can easily read the contents of the message.

According to one embodiment of the present disclosure, a first electronic device (1000) can transmit an encrypted message to a second electronic device (1100) through an MNO (1200). Even if the encrypted message is transmitted to a third electronic device (1300), the third electronic device (1300) may fail to decrypt the encrypted message because it does not have a session key for decryption, and may not be able to read the contents of the message. If the network mistakenly transmits the message to a third party other than the intended recipient, the message may have a lower security risk.

Even if a third electronic device (1300) intercepts a message or eavesdrops on a phone call, the third electronic device (1300) may fail to decrypt the encrypted message and may not be able to read the contents of the message because it does not have the session key for decryption.

According to one embodiment of the present disclosure, a first electronic device for transmitting a message in a wireless communication system is provided. The first electronic device includes a transceiver and at least one processor connected to the transceiver. The at least one processor obtains a first encrypted message in which a first message is encrypted based on a first session key. The at least one processor transmits the first encrypted message to a second electronic device. The at least one processor obtains a second session key based on the first message and the first session key. The at least one processor obtains a second encrypted message in which the second message is encrypted based on the second session key. The at least one processor transmits the second encrypted message to the second electronic device.

According to one embodiment of the present disclosure, at least one processor

According to one embodiment of the present disclosure, at least one processor

According to one embodiment of the present disclosure, at least one processor generates first comparison data having an encrypted user code based on a first session key. The at least one processor transmits the first comparison data and the user code to a second electronic device.

According to one embodiment of the present disclosure, at least one processor generates a user code based on registration information of a second electronic device registered to the first electronic device.

According to one embodiment of the present disclosure, at least one processor transmits a user code and a session key mapped to the user code to the second electronic device. The registration information includes at least one of name information, address information, birthday information, or a random code.

According to one embodiment of the present disclosure, at least one processor identifies whether a second session key of a second electronic device and a second session key of a first electronic device are synchronized.

According to one embodiment of the present disclosure, at least one processor generates a first session key. The at least one processor transmits the first session key to a second electronic device.

According to one embodiment of the present disclosure, when a success delivery report of a second message is received, at least one processor updates the second session key with a third session key obtained based on the second message and the second session key.

According to one embodiment of the present disclosure, a second electronic device for receiving a message in a wireless communication system is provided. The second electronic device includes a memory storing a session key, a transceiver; and at least one processor connected to the transceiver. The at least one processor receives a first encrypted message in which a first message is encrypted from the first electronic device. The at least one processor obtains a first decrypted message in which the first encrypted message is decrypted based on the stored session key. The at least one processor obtains a second session key based on the first decrypted message and the session key. The at least one processor receives a second encrypted message in which the second message is encrypted from the first electronic device. The at least one processor obtains a second decrypted message in which the second encrypted message is decrypted based on the second session key.

According to one embodiment of the present disclosure, at least one processor maps the originating number of the first decrypted message to a name of a contact when the first decrypted message is obtained and the originating number of the first decrypted message is an unregistered number.

According to one embodiment of the present disclosure, at least one processor receives a user code and first comparison data from a first electronic device. If a session key is mapped to the user code, the at least one processor obtains second comparison data in which the user code is encrypted based on the session key. If the first comparison data and the second comparison data match, the at least one processor obtains a first decrypted message in which the first encrypted message is decrypted based on the session key.

According to one embodiment of the present disclosure, at least one processor manages the sending number of the first message as an insecure number if the session key is not mapped to a received user code, or if the first comparison data and the second comparison data do not match.

According to one embodiment of the present disclosure, at least one processor receives a user code and a session key mapped to the user code from a first electronic device. The user code is generated based on registration information registered by the second electronic device (1100) to the first electronic device (1000). The registration information includes at least one of name information, address information, birthday information, or a random code.

According to one embodiment of the present disclosure, at least one processor identifies whether a second session key of a first electronic device and a second session key of a second electronic device have been identified.

According to one embodiment of the present disclosure, at least one processor receives a first session key from a first electronic device. The stored session key includes the first session key.

According to one embodiment of the present disclosure, a computer-readable recording medium having recorded thereon a program for executing the above-described method can be provided.

The method according to one embodiment of the present disclosure may be implemented in software. When the method of the present disclosure is implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors in an electronic device such as a terminal. The one or more programs include instructions that cause the electronic device to execute the methods according to the embodiments described in the claims or specification of the present disclosure.

These programs (software modules, software) may be stored in a random access memory, a non-volatile memory including flash memory, a read only memory (ROM), an electrically erasable programmable read only memory (EEPROM), a magnetic disc storage device, a compact disc-ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage, a magnetic cassette. Or, they may be stored in a memory composed of a combination of some or all of these. In addition, each component memory may be included in multiple numbers.

Additionally, the program may be stored in an attachable storage device that is accessible via a communications network, such as the Internet, an Intranet, a local area network (LAN), a wide area network (WAN), or a storage area network (SAN), or a combination thereof. The storage device may be connected to a device performing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communications network may be connected to a device performing an embodiment of the present disclosure.

According to various embodiments, each component (e.g., module, part or program) of the above-described components may include a single or multiple entities. According to various embodiments, one or more components or operations of the above-described components may be omitted, or one or more other components or operations may be added.

In the specific embodiments of the present disclosure described above, the components included in the disclosure are expressed in the singular or plural form depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for the convenience of explanation, and the present disclosure is not limited to the singular or plural components, and even if a component is expressed in the plural form, it may be composed of the singular form, or even if a component is expressed in the singular form, it may be composed of the plural form.

In addition, the terms used in this disclosure are only used to describe specific embodiments and are not intended to limit the present disclosure. For example, when expressed as a message, the same can be applied to various types of information such as phone calls and messages.

Alternatively or additionally, a plurality of components (e.g., modules, parts or programs) may be integrated into a single component. In such a case, the integrated component may perform one or more functions of each of the plurality of components in a manner identical to or similar to that performed by the corresponding component among the plurality of components prior to the integration.

According to various embodiments, the operations performed by a module, unit, program or other component may be performed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be performed in a different order, omitted, or one or more other operations may be added.

The scope of the present disclosure is indicated by the claims described below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present disclosure.

Claims (20)

In a first electronic device (1000) for transmitting a message in a wireless communication system,
Transmitter and receiver (1020); and
At least one processor (1010) connected to the transceiver,
At least one processor (1010) above,
Obtaining a first encrypted message in which the first message is encrypted based on the first session key,
Transmitting the first encrypted message to the second electronic device (1100),
Obtaining a second session key based on the first message and the first session key;
Obtaining a second encrypted message in which the second message is encrypted based on the second session key;
A first electronic device transmitting the second encrypted message to the second electronic device.
In paragraph 1,
At least one processor (1010) above,
Generate first comparison data encrypted with a user code based on the first session key,
A first electronic device that transmits the first comparison data and the user code to the second electronic device (1100).
In the second paragraph,
At least one processor (1010) above,
Generate the user code based on the registration information of the second electronic device (1100) registered in the first electronic device (1000),
Transmitting the user code and the session key mapped to the user code to the second electronic device (1100),
A first electronic device, wherein the registration information includes at least one of name information, address information, birthday information, or a random code.
In paragraph 1,
At least one processor (1010) above,
A first electronic device that identifies whether the second session key of the first electronic device (1000) and the second session key of the second electronic device (1100) are synchronized.
In the first paragraph,
At least one processor (1010) above,
Generate the above first session key,
A first electronic device that transmits the first session key to a second electronic device (1100).
In paragraph 4,
The step of identifying whether the second session key of the first electronic device (1000) is synchronized with the second session key of the second electronic device (1100) is:
A first electronic device, comprising a step of updating the second session key with a third session key obtained based on the second message and the second session key, if a success delivery report of the second message is received.
In a second electronic device (1100) receiving a message in a wireless communication system,
Memory to store session keys;
Transmitter and receiver (1120); and
At least one processor (1110) connected to the transceiver,
At least one processor (1110) above,
Receive a first encrypted message from a first electronic device (1000), wherein the first message is encrypted;
Obtaining a first decrypted message in which the first encrypted message is decrypted based on the stored session key;
Obtaining a second session key based on the first decryption message and the session key;
Receive a second encrypted message from a first electronic device (1000), wherein the second message is encrypted;
A second electronic device, which obtains a second decrypted message based on the second session key, wherein the second encrypted message is decrypted.
In paragraph 7,
At least one processor (1110) above,
A second electronic device that maps the sender number of the first decrypted message to a contact name when the first decrypted message is obtained and the sender number of the first decrypted message is an unregistered number.
In paragraph 7,
The step of obtaining the first decryption message is:
A step of receiving a user code and first comparison data from the first electronic device (1000);
If the session key is mapped to the user code, a step of obtaining second comparison data in which the user code is encrypted based on the session key; and
A second electronic device, comprising a step of obtaining the first decrypted message in which the first encrypted message is decrypted based on the session key when the first comparison data and the second comparison data match.
In Article 9,
A second electronic device that manages the sending number of the first message as an insecure number if the session key is not mapped to the received user code or if the first comparison data and the second comparison data do not match.
In Article 10,
At least one processor (1110) above,
Receive the user code and the session key mapped to the user code from the first electronic device (1000),
The above user code is generated based on the registration information registered by the second electronic device (1100) to the first electronic device (1000),
A second electronic device, wherein the registration information includes at least one of name information, address information, birthday information, or a random code.
In paragraph 7,
At least one processor (1110) above,
A second electronic device that identifies whether the second session key of the second electronic device (1100) and the second session key of the first electronic device (1000) are synchronized.
In paragraph 7,
The at least one processor (1110) receives a first session key from the first electronic device (1000),
A second electronic device, wherein the session key comprises the first session key.
A method for transmitting a message by a first electronic device (1000) in a wireless communication system,
A step of obtaining a first encrypted message in which the first message is encrypted based on the first session key;
A step of transmitting the first encrypted message to a second electronic device (1100);
A step of obtaining a second session key based on the first message and the first session key;
A step of obtaining a second encrypted message in which the second message is encrypted based on the second session key; and
A method comprising the step of transmitting the second encrypted message to the second electronic device (1100).
In Article 14,
A step of generating first comparison data in which a user code is encrypted based on the first session key; and
A method further comprising the step of transmitting the first comparison data and the user code to the second electronic device (1100).
In Article 15,
A step of generating the user code based on the registration information of the second electronic device (1100) registered in the first electronic device (1000); and
Further comprising a step of transmitting the user code and the session key mapped to the user code to the second electronic device (1100);
A method wherein the registration information includes at least one of name information, address information, birthday information, or a random code.
A method for a second electronic device (1100) to receive a message in a wireless communication system is as follows:
A step of receiving a first encrypted message, wherein the first message is encrypted, from a first electronic device (1000);
A step of obtaining a first decrypted message in which the first encrypted message is decrypted based on the stored session key;
A step of obtaining a second session key based on the first decryption message and the session key;
A step of receiving a second encrypted message from a first electronic device (1000), wherein the second message is encrypted; and
A method comprising the step of obtaining a second decrypted message, wherein the second encrypted message is decrypted based on the second session key.
In Article 17,
A second electronic device further comprising a step of mapping the sender number of the first decrypted message to a name of a contact when the first decrypted message is obtained and the sender number of the first decrypted message is an unregistered number.
In Article 17,
The step of obtaining the first decryption message is:
A step of receiving a user code and first comparison data from the first electronic device (1000);
If the session key is mapped to the user code, a step of obtaining second comparison data in which the user code is encrypted based on the session key; and
A method comprising the step of obtaining the first decrypted message in which the first encrypted message is decrypted based on the session key when the first comparison data and the second comparison data match.
In Article 19,
A method further comprising the step of managing the sending number of the first message as an insecure number if the session key is not mapped to the received user code or if the first comparison data and the second comparison data do not match.

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