WO2012088661A1

WO2012088661A1 - Method for enhancing usage security of subscriber identity module

Info

Publication number: WO2012088661A1
Application number: PCT/CN2010/080365
Authority: WO
Inventors: 黄正全
Original assignee: 北京邮电大学
Priority date: 2010-12-28
Filing date: 2010-12-28
Publication date: 2012-07-05

Abstract

The present invention belongs to the technical field of mobile communication and smart card application, and specially provides a method for enhancing the security of a subscriber identity module (SIM). For the phenomenon that illegal copy and embezzlement of the SIM often exist in a mobile communication system, the invention adopts the idea of combination of active defence and dynamic management. By performing function expansion and enhancement on a part of the function entities in the mobile communication system and adding new security data and operation process, the invention realizes the hiding and protection of the original security data so that the user can actively perform the prevention in advance, supervision in process, and postmortem control on the security during the usage of the SIM. Thus the illegal copy and embezzlement of the SIM are prevented and the profits of the subscriber and the operator are protected.

Description

Ways to enhance the security of user identity modules

Technical field

The invention belongs to the technical field of mobile communication and smart card application, and particularly relates to an enhanced user identification module (Subscriber Identity) Module, SIM) uses a secure method.

Background technique

In the mobile wireless communication system, the SIM is used to correlate information related to the user, and at the same time, the related business information signed by the user is also saved, so the security of the SIM is very important, and if the information is leaked or copied, it may lead to illegal use. It is a serious hazard to normal communication services.

Due to the limitations of SIM's own technology and production and sales conditions, and the production and operation of mobile communication systems involve many vendors, channels and links, the phenomenon of illegal copying and misappropriation of SIM has occurred from time to time. The analysis from the circulation use process of SIM, resulting in the phenomenon of illegal copying or misappropriation of SIM can be divided into the following two types:

The first situation occurs in the distribution of SIM. Due to the numerous distribution links and channels involved, the SIM may have been illegally copied by the criminals before being distributed to the user, but the user is unaware; after that, once the user is enabled The copied SIM gives the pirate a chance to use it, and the thief can use the copied SIM to illegally use the communication service contracted by the normal user, causing economic or other losses to the user.

The second case occurs during the use of the SIM. Due to improper use or other reasons, the SIM is illegally copied and used by the user, but the user cannot know or control in time, thereby causing serious consequences.

The illegal copying or misappropriation of SIM caused by the above two situations will seriously hinder the normal development of communication services, causing serious impacts on operators and mobile users, and even lead to huge economic losses and civil disputes.

At present, the security protection measures for SIM security are usually concentrated in the manufacturing stage of SIM. Once the SIM production is completed, its security and confidential data are unchanged, and the SIM can only be used by the physical security of the SIM itself. Protection is a static protection method. As long as the data is cracked or copied, the security of the SIM is completely destroyed and can no longer be put into use. At the same time, for the user, due to the lack of effective means and channels, it is impossible to know and control the security status of SIM, and it is impossible to actively participate in the security protection process of SIM. Only when their interests are violated, they know the security of their SIM. The status has gone wrong, and it can be seen that the user's protection against SIM security is always in a passive protection state. Similarly, for operators, it is always in a passive, static state of protection. Although some dynamic and active protection methods and patents have been proposed for the illegal copying and misappropriation of SIM, they are usually after-the-fact detection or control means that only when the illegal copying and misappropriation of SIM occurs It may be monitored; and monitoring measures are usually deployed on the network side of the communication system. Therefore, the process and results are only known to the operator, but the user has no knowledge, can not prove, and can not avoid further harm in time, can not effectively protect Your own legitimate rights and interests will inevitably not cause disputes with operators; in addition, once the SIM is stolen, users can only replace SIM if they want to solve this problem, which will add a lot of trouble to users and operators. The operator's business will be affected, and the operator's business quality and brand effect will inevitably be unaffected.

In view of the above-mentioned phenomena and problems, the present invention aims to provide a method for preventing unauthorized use of SIM by allowing users to actively participate and coordinate monitoring by operators, and realize active management and dynamic monitoring for visualizing the security state of the SIM throughout the use process. From passive defense to active defense, from static management to dynamic management.

It can be seen from the above background that the SIM according to the present invention includes, but is not limited to, SIM in a GSM system, UIM in a CDMA system (User Identity Model (User Identity Module), USIM (User Service) in 3G (3rd Generation, 3rd Generation) Mobile Communication System Identity Module, User Service Identification Module, other systems employing similar Subscriber Identity Modules/Smart Cards are also applicable to the spirit and spirit of the present invention.

Summary of the invention

The present invention addresses the above problems, adopts the idea of combining active defense and dynamic management, and expands and enhances the related functional entities in the mobile communication system to add new security data and operation flow, thereby realizing the hiding of the original security data. And protection, so that users can proactively prevent, monitor, and control the security of the SIM, prevent illegal copying and misappropriation of the SIM, and protect the interests of users and operators.

The method for enhancing security of the SIM of the present invention comprises three phases: first, performing SIM secure registration when the SIM first accesses the network, completing the function of querying the freshness of the SIM and setting new security data; and then, the SIM is normal. During the use process, the new security data is used to check the security status of the SIM, and the new security data can be updated and dynamically managed at the same time. Finally, if the status is abnormal, the user is prompted to control the use of the SIM to form a complete active protection. system.

The method for enhancing security of the SIM of the present invention specifically includes the following operations:

1) Check the freshness of the SIM. When the SIM is registered for the first time, the system needs to check the freshness of the SIM, that is, check whether the SIM is the first time to access the network, whether it has been registered in the network or has been used. The communication system is based on SIM related information such as International Mobile Subscriber Identity/Temporary Mobile Subscriber Identification Number (IMSI/TMSI, International) Mobile Subscriber Identity/Temporary Mobile Subscriber Identity), query system records, and feed back the test results to the user; at the same time, record the ME related information used for registration of this SIM network access, such as International Mobile Equipment Identification Number (IMEI, International) Mobile Equipment Identity) for later use. In this way, when an abnormality occurs in the inspection result, the user can stop using the SIM in time to prevent the occurrence of a hazard.

2) Generate an activation code. After passing the freshness check, two data are randomly generated by the system network side as an activation code (AC, Activation). Code) is sent to the user side, one as the SIM activation code (SAC, SIM Activation Code) and the other as the mobile terminal (ME, Mobile) Equipment) Activation Code (MAC, ME Activation) Code). Each SIM and its ME have a corresponding AC. The network side saves the correspondence between the SIM/ME and the activation code for checking. Since the AC is field-generated data, it has strong timeliness and randomness, and is not easy to be copied and stolen, thereby preventing illegal copying and misappropriation of the SIM, and also preventing the use of SIMs that are illegally copied in advance because of illegally copied SIMs. There is no matching SAC. At the same time, it can also improve the security of the ME.

3) Set the security code. In order to enhance the security of SIM usage, enhance user initiative and controllability of SIM, users set a data as SIM security code (SC, Security). Code) and sent to the network side. Each SIM has a corresponding SC. Similarly, the SC can prevent copying or embedding the SIM and prevent the use of SIMs that were previously illegally copied.

4) Generate a Ki mask. Since the SIM is once manufactured, the encryption key Ki therein is fixed, resulting in easy cracking and copying. In order to improve the security of Ki, the present invention adopts a multi-factor combination method to securely combine Ki with AC (SAC, MAC) and SC, and generates a Ki mask according to the following formula 1 (KiM, Ki) Mask):

KiM=f(Ki,SAC,MAC,SC) (1)

Among them, f() represents a functional relationship or algorithm implementation, which implements a secure combination of several data such as Ki, SAC, MAC, and SC.

Used to replace the original encryption key Ki. In the subsequent communication process, KiM is used instead of Ki for related authentication and encryption processing. Because KiM is generated by field-generated data combination, it has strong timeliness, which not only prevents SIM from being copied and stolen, but also prevents the use of illegally copied SIMs, which prevents pre-emptive and in-process monitoring.

5) Generate an IMSI mask. Similarly, once the SIM is manufactured, the IMSI is fixed and easily copied and stolen. In order to protect the security of the IMSI, the present invention combines the IMSI with the AC and the SC by using a multi-factor combination method, as shown in the following formula 2,

IMSI_M= g(IMSI,SAC,MAC,SC) (2)

Among them, g () represents a functional relationship or algorithm implementation, to achieve a safe combination of several data such as Ki, SAC, MAC, SC.

Generate IMSI mask (IMSI_M, IMSI) Mask), instead of IMSI, hides and protects the real IMSI. In this way, in addition to the real IMSI required when the SIM first accesses the network, IMSI_M is used instead of the real IMSI when other IMSIs are needed, and the real IMSI is no longer used, thereby protecting the user's real identity and SIM security. At the same time, because IMSI_M is generated by field-generated data combination, it has strong timeliness and randomness, which not only prevents SIM from being copied and stolen, but also prevents illegal copying of SIM, preventing precaution and monitoring. The role.

6) Compare the serial number used by the SIM. The present invention designs a new data - SIM uses the serial number (SUSN, SIM Used) Serial Number), used to record the number of SIM access times. SUSE is initialized when the SIM first enters the network. The user side and the network side simultaneously record and update SUSE. SUSE adopts the method of loop counting, which can be generated by the user side or the network side and then sent to the other party. It can also be calculated by the user side and the network side respectively. When the SIM is authenticated every time, the system compares the SUSEs stored on the user side and the network side to check whether they are consistent, so as to determine whether there is a misappropriation of the SIM. If the SUSEs on both sides are the same, or within a reasonable error range, the SIM is not stolen; otherwise, the SIM is stolen and the user is prompted to process.

7) SIM security update. During the use of the SIM, the user can dynamically update the newly added security data in the SIM, including AC, SC, KiM, IMSI_M, etc., so that the newly added security and confidential data is constantly changed to avoid being copied and stolen, and further improved. SIM and the security of its use.

8) SIM re-register. Under normal circumstances, if the SIM is found to be stolen, the user can only replace the SIM, and the procedures and procedures are troublesome, resulting in the inability to use the communication service in time. In this regard, the present invention adopts the SIM re-registration method, and the user actively updates the relevant security data in the SIM, and regenerates new security and confidential data, including AC, SC, KiM, IMSI_M, SUSE, etc., to copy and steal. The SIM has no effect, but its SIM can still be used, achieving the same effect and purpose as the direct SIM replacement, but avoiding the troubles and links of directly replacing the SIM.

9) Machine card association verification. In order to ensure the security of the SIM in one step, the present invention also checks and limits the use environment of the SIM, and the limited SIM can only be used on the ME that has been registered and authenticated, that is, the machine card association verification. When the SIM is registered for the first time, the ME is registered in the SIM and the network side, and the related information of the ME is recorded in the SIM, including the IMEI; the network side mainly increases the association information between the ME and the SIM, thus forming a The first layer of the card binding relationship between the SIM and the ME. The network side generates AC (SAC, MAC) for both SIM and ME, and then uses the SAC and MAC to jointly generate KiM, so that SIM and ME form a second layer card binding relationship. After that, each time the SIM is authenticated to the network, the binding relationship between the two layers can be verified. Since the IMEI is easy to forge, the present invention does not verify the first layer binding relationship, but mainly verifies the second layer machine card binding relationship. There is no special explanation in the future, and the machine card binding relationship refers to the second layer machine card binding relationship. By recalculating KiM, it is possible to verify whether the SIM and ME are registered pairs of SIM/ME. If there is a difference between the SIM and the ME, the calculated KiM will be different, which will cause the SIM to enter the network authentication failure. In this way, the use of the copy SIM is effectively prevented, and even if the SIM is copied, if there is no matching ME, it cannot be successful. Therefore, SIM binding security is enhanced by binding to the ME. If the user needs to replace the new ME, you need to unbind the SIM card, unbind the SIM from the old ME, and then bind the SIM to the new ME to re-set the security registration. So that the SIM can be used normally on the new ME. Through this series of binding and unbinding operations, it can be ensured that the ME where the SIM is located is authenticated by the user and is safe, thus ensuring the security of the SIM.

10) Machine card rebinding. As mentioned earlier, when the SIM first registers with the network, it registers and binds the ME used at the time. After that, if the user needs to replace the ME, the new ME needs to be bound to the SIM, that is, the card is re-bound. When the SIM uses a new ME, since the new ME does not have a corresponding MAC, KiM cannot be generated. Therefore, if the KiM is still used for network authentication, it will cause a failure. At this point, the user can manually initiate the operation and complete the card. Bind. Due to the lack of MAC, KiM cannot be generated. Although Ki can be used directly at this time, the present invention still does not use Ki for the purpose of preventing the use of the copied SIM, but uses the following form to generate the required KiM using the following form:

KiM=f(Ki,SAC,SAC,SC) (3)

Then, the KiM generated by the above method encrypts the data of the old and new MEs and sends the data to the network side for network access authentication. After the authentication is successful, the related confidential data is regenerated, and the machine card is bound. The security replacement of the ME is completed, and the security data of the SIM is dynamically updated to enhance the security of the SIM.

Only after the machine card is re-bound, the new ME is registered in the system and generates a MAC for it, and the SIM can successfully access the network.

Through the above operations, the present invention firstly combines the secret data generated on-site when the SIM is first accessed, and generates new confidential data to replace the original static secret data, thereby improving the security of the data and The data is dynamically updated and managed to achieve active defense. Secondly, the new confidential data is generated through negotiation. The security of the SIM is unilaterally protected by the user side, and the network side and the user side are cooperatively protected, which can effectively prevent the SIM from being copied and Theft; finally, through the machine card association verification, the SIM environment is authenticated and protected to further enhance the security during SIM use. The above various operating procedures can be flexibly combined to form a complete protection system for pre-prevention, in-process monitoring and post-event control.

The enhanced SIM security system of the present invention adds new security data and operation flow without changing the structure of the communication system, thereby expanding the functions and functions of the related functional entities, thereby achieving the purpose of enhancing the security of the SIM use. The system includes two parts: the user side and the network side.

The user side includes a SIM and an ME. The SIM stores various confidential data such as mobile user identity information and service information, such as IMSI, Ki, and the like. ME refers to devices with mobile communication functions, such as mobile phones, personal digital processing, mobile communication data cards, portable mobile computers, and the like.

The network side generally refers to the network that the operator provides the mobile communication service. For the sake of simplicity, the present invention only describes related functional entities related to the authentication of the mobile user identity and service, including the home subscriber server (HSS, Home). Subscriber Server), Mobile Switching Center/Visit Location Register (MSC/VLR, Mobile Switching Center/Visiting) Location Register), Device Identification Register (EIR, Equipment Identity) Register) and other functional entities; HSS specifically includes home location register (HLR, Home Location) Register) and functional entities such as the Authentication Center (AuC).

The new secret data generated by the method of the present invention, such as KiM, IMSI_M, SUSE, etc., needs to be stored in a security function module or entity in the system. It can be stored in existing functional modules or entities in the communication system, such as SIM, HSS/AuC/HLR; it can also be saved with new functional modules or entities.

Some secret data generated by the user on the user side, such as KiM, IMSI_M, SUSE, etc., may be stored in the SIM or in the ME. If it is stored in the ME, the corresponding backup measures must be set so that when the user replaces the new ME, the relevant data can be transferred to the new ME to ensure that the SIM can still be used normally.

The new secret data generated by the invention on the network side, such as KiM, IMSI_M, SUSE, etc., may be stored in one or more functional entities, such as HSS/AuC/HLR, according to a specific network structure.

The IMSI_M and KiM generated by the method of the present invention can be directly calculated and stored in the system, or can be temporarily calculated only when needed, and avoid long-term storage.

The method and the flow of the present invention can be implemented as an ME application on the user side, as a SIM application, or a combination of the two.

The method and the process of the present invention can be used alone, one process can implement one method, or only one method can be used; or can be combined and used to combine multiple methods to form one or more processes. A complete set of protection systems or business processes.

Advantageous effects of the present invention include:

1. Without changing the structure and equipment of the mobile communication network, by adding corresponding functional algorithms and programs, the security of the SIM use process can be greatly enhanced, and the phenomenon of illegal copying and misappropriation of SIM can be effectively prevented, and operators and User's loss.

2. It is possible for the operator to clearly understand which part of the SIM circulation process has been illegally copied or stolen, so that the management and control of the SIM circulation link can be enhanced in a targeted manner.

3. The user can take the initiative to master the security status of the SIM, so as to prevent, monitor, and control in advance, detect and prevent theft in time, and avoid losses and harms.

4. Operators and users can prove that there is illegal copying or misappropriation in which link, so that they can distinguish responsibility and bear corresponding consequences, avoid unnecessary disputes and affect normal business development.

5. Operators can enhance user confidence in the security of SIM and communication services, improve service quality and brand image, and thus enhance user loyalty.

DRAWINGS

1 is a simplified schematic diagram of a mobile communication system, showing only some of the functional entities associated with the present invention.

2 is a schematic diagram of an implementation of a system structure of the present invention.

Figure 3 is a general flow chart of SIM security registration.

FIG. 4 is a schematic diagram of a detailed flow of data interaction and operation during SIM security registration.

Figure 5 is a schematic diagram of a generation method of KiM.

Figure 6 is a schematic structural view of an IMSI.

Fig. 7 is a schematic structural view of an IMSI_M.

FIG. 8 is a schematic diagram of a generation manner of MSIN_M.

FIG. 9 is a schematic diagram of a SIM network verification process.

FIG. 10 is a schematic diagram of an update SC operation flow.

Figure 11 is a general flow chart of SIM re-safe registration.

Figure 12 is a schematic diagram of the detailed process of SIM re-authentication registration.

Figure 13 is a schematic diagram of the process of rebinding the card.

Figure 18 is a schematic diagram showing the operation function of the method of the present invention on the user side.

The method for enhancing the security of SIM use provided by the present invention will be described in detail below with reference to the accompanying drawings.

detailed description

As shown in FIG. 1, in the mobile communication system, confidential data such as IMSI/TMSI/Ki is stored in the SIM. IMSI is used to identify the identity of the user and the business appointment relationship between the user and the network. The TMSI is allocated by the MSC/VLR for each incoming user after the user enters the network, and is used to keep the IMSI confidential to communicate with the IMSI. Ki is a communication encryption key for user identity authentication and communication encryption. IMEI is the unique device identification code of the ME. Each ME has its own unique device ID. In the network side, different functional entities are used to store corresponding data, such as IMSI, Ki in HSS/AuC/HLR, IMEI in EIR, and TMSI in MSC/VLR.

As shown in FIG. 2, an implementation of the system structure of the present invention performs functional expansion on related functional entities on the user side and the network side, mainly by adding some new confidential data, as shown by the italicized text symbols in the figure. Add SAC, SC, SUSE, KiM, IMSI_M in the SIM, where KiM and IMSI_M are obtained by the SIM on-site when the network is authenticated; MAC is added in the ME; similarly, it is added to the user side in different functional entities on the network side. New security data. On the network side, in order to reduce the amount of communication and the amount of calculation between entities, this embodiment directly stores KiM and IMSI_M.

The enhanced SIM uses security method of the present invention, when the system is initially established, or when each new SIM joins, the system establishes relevant recording and allocation storage space for each SIM, for storing the required requirements of the present invention. New safety data and records.

The enhanced SIM of the present invention uses a method of security, first performing a SIM secure registration operation. It is done when the user first enables SIM. This operation can be initiated either by the user, such as operating the SIM application menu, or automatically by the SIM. This embodiment is described by taking the method initiated by the user as an example. The overall process of the SIM security registration operation is shown in Figure 3. The data interaction and operation flow between the user side and the network side is shown in Figure 4. Figure 4 is not completely in accordance with the flow shown in Figure 3, but is partially optimized. The SIM secure registration operation includes the following steps:

S301, start SIM security registration. When the user first enables the SIM, the SIM security registration process is initiated by operating the SIM application menu, and the SIM security registration request is sent to the network side.

S302, check the freshness of the SIM. After receiving the SIM security registration request from the user side, the network side checks the internal related database to check whether the SIM has been registered or has been used, so as to determine whether the SIM is fresh, that is, whether it is the first Used in the network. This embodiment checks the freshness of the SIM by checking whether SUSE is 0.

S303. Determine the freshness of the SIM. The network side determines whether the SIM is fresh according to the check result, that is, whether SUSE is 0. If it is not fresh, prompt the user and end the operation; otherwise, proceed to the next step.

S304. Generate an AC, including SAC and MAC. The network side generates a SAC for the SIM that passes the freshness check, and simultaneously generates a MAC for the ME and sends it to the user side.

S305, setting SC. The user side sets the SC for the SIM and sends it to the network side.

S306, generating KiM. The system combines Ki generated according to the SAC, MAC and SC generated in the field, and generates KiM in combination to replace Ki. One way of generating KiM is shown in Figure 5. Several data are encrypted by the existing secure encryption algorithm in SIM, such as DES/3DES algorithm, to obtain KiM, so that the original Ki that may have been copied can be updated. For the purpose of protecting the Ki and SIM security for new data. If the data lengths of the SAC, MAC, and SC do not match the data length of the Ki or the algorithm, the SAC, MAC, and SC need to be appropriately transformed during the operation so that the data length matches the data length of the Ki or the algorithm. In the embodiment of the present invention, KiM is generated in accordance with the formula 1 of the content section of the invention unless otherwise specified.

S307. Generate IMSI_M. The system combines the generated SAC, MAC and SC, combined with the IMSI, to generate IMSI_M, which is used to hide and replace the IMSI, so as to protect the true identity of the user. The data structure of IMSI is shown in Figure 6, where the mobile country code (MCC, Mobile) Country Code), Mobile Network Code (MNC, Mobile Network) Code) generally does not allow modification. Therefore, this embodiment only applies to the mobile subscriber identification number (MSIN, Mobile Subscriber Identification). Number) is updated, called MSIN mask (MSIN_M, MSIN Mask), the structure of IMSI_M is shown in Figure 7, from which it can be seen that generating MSIN_M is equivalent to generating IMSI_M. Therefore, IMSI_M can be generated by generating MSIN_M. MSIN_M is generated as shown in Equation 3:

MSIN_M= h(MSIN,SAC,MAC,SC) (4)

Where h() represents a functional relationship or algorithm implementation, which is a secure combination of several data such as MSIN, SAC, MAC, and SC. A generation method of MSIN_M is as shown in FIG. 8 , and the original security encryption algorithm, such as DES/3DES algorithm, is used for combined encryption to update the original MSIN that may have been copied into new data. The purpose of protecting the security of MSIN, IMSI and SIM is achieved. In the implementation process, the lengths of several data such as MSIN, SAC, MAC, and SC can be appropriately changed or set according to the needs of the algorithm.

S308, configure SUSE. When the system initially creates a SIM-related record, it needs to allocate storage space for SUSE and initialize it to 0, indicating that the SIM is fresh and has not been used. In the SIM, it can be implemented by adding a new record file or adding a new field based on the existing record file; on the network side, a new data record can be created, or a new data record can be added through the existing data record about the SIM information. The way the field is implemented. In this operation, since the SIM is the first network access authentication, if the above operation is successful, SUSE must be set to 1.

S309, completing the SIM security registration process. The user side and the network side respectively store corresponding data.

In the above process, the setting SC may also be placed at the beginning of the program, and the generated SC and the secure registration request are simultaneously sent to the network side, and the relevant data is saved only after both parties receive the confirmation information. In the process of the method of the present invention, in order to ensure the reliability and consistency of the interaction data, each time the user side and the network side negotiate to generate data, the sender needs to receive the confirmation message fed back by the receiver before ending the book. Sub-operational process. The detailed operation flow and interactive content are shown in Figure 4.

The enhanced SIM uses security method of the present invention to provide a method for monitoring SIM security in the event that after the SIM is officially enabled, the user can check the security of the SIM at any time to check whether it is copied or stolen. It is implemented by verifying KiM and comparing SUSE when the SIM is registered in the network. The process is shown in Figure 9, including the following aspects:

S901: The SIM initiates an incoming network verification operation every time the network is logged in to check the security during the use of the SIM.

S902, temporarily generating KiM. The user side generates a KiM by using a combination of MAC, SAC, SC, and Ki. Since the calculation is performed by MAC and SAC here, only when the SCs saved by the ME and the SIM are consistent, the calculated KiM is correct, that is, the machine card association verification is implemented; otherwise, the calculated KiM is wrong. , indicating that the machine card association error.

S903, the SUSE (denoted as SUSE_SIM) saved by itself is encrypted by KiM (represented by KiM (SUSE_SIM)) and sent to the network side;

S904: The network side decrypts the received data by using the corresponding KiM saved by itself, and obtains SUSE_SIM. If the KiM used for encryption is wrong, the decrypted SUSE_SIM is definitely wrong, which will cause subsequent authentication failures.

S905, the network side compares SUSE. The network side compares the SUSE_SIM with the corresponding SUSE (named SUSE_Net) saved by itself; if the SUSEs on both sides are the same (ie, SUSE_SIM=SUSE_Net), the SIM is not stolen, and the message that SUSE is successful is returned; if not, then Indicates that the SIM is stolen and returns a message that the SUSE comparison failed. This step compares SUSE and completes KiM verification and machine card association verification.

S906: The user side determines the SUSE comparison result according to the return message on the network side, and makes a next operation selection. If the comparison is successful, continue to execute; otherwise, prompt the user and end the operation.

S907, synchronously updating SUSE. After the above authentication succeeds, the user side and the network synchronize to update SUSE. In order to prevent the user side from interacting with the network again, the embodiment adopts synchronous update by the user side and the network side respectively, and the update adopts a cyclic increment counting manner. When the old SUSE value reaches the maximum value, the SUSE value after the update operation is 1. The maximum value of SUSE can be flexibly set according to the system conditions.

S908, save SUSE. The latest SUSE is saved on the user side and the network side. End the operation.

The enhanced SIM using security method of the present invention allows the user to dynamically manage and update the security of the SIM during the process of using the SIM, which is implemented by updating part of the security data in the SIM to prevent The SIM is illegally copied or stolen, improving the security of the SIM. The related process is shown in Figure 10 and includes:

S1001: During the use of the SIM, the user may initiate an operation of updating the SC according to the situation or needs to update related security data in the SIM, thereby improving the security of the SIM.

S1002: After the user initiates the operation of updating the SC, set a new SC, and then send a request for updating the SC and a new SC to the network side.

S1003: The network side receives the update SC request of the user, and determines whether to accept the request. If the request is received, the AC (SAC, MAC) is regenerated, and then a series of processes for updating other security data are started one after another.

S1004, update SC. The network side updates the SC stored by itself with the new SC sent by the user side.

S1005, update KiM. The network side regenerates the KiM with the new SAC, MAC, and SC.

S1006, update IMSI_M. The network side regenerates the IMSI_M with the new SAC, MAC, and SC.

S1007: If all the update operations on the network side are successful, send a message that the SC update is successful to the user side, and send the new SAC and MAC to the user side.

S1008: The user side determines, according to the message sent by the network side, whether the update SC operation on the network side is successful. If it fails, the operation ends; otherwise, the operation continues.

S1009, update AC (SAC, MAC). The user side updates the AC stored internally by the AC (SAC, MAC) sent by the network side, that is, the SIM updates the SAC, and the ME updates the MAC.

S1010, update SC. After the network side updates the SC successfully, the user side can update its own SC. SIM updates SC.

S1011, update KiM. The user side regenerates KiM with the new AC (SAC, MAC) and SC.

S1012, updating IMSI_M/MSIN_M. The user side regenerates IMSI_M/MSIN_M with the new AC (SAC, MAC) and SC.

S1013: After the foregoing operations are completed, the execution result is fed back to the user and the network side.

The method for enhancing the SIM using security of the present invention provides an operation method for controlling the security of the SIM after use. After the user finds that the SIM is copied or stolen, the SIM is re-registered securely, that is, the SIM is re-registered to avoid direct replacement. The troubles and links of SIM. The overall process of SIM re-registration is shown in Figure 11, which includes the following stages:

S1101, regenerating AC (SAC, MAC).

S1102, reset the SC.

S1103, regenerate KiM.

S1104, regenerating the IMSI_M.

S1105, reset SUSE.

The detailed process of the related embodiment is as shown in FIG. 12, and includes:

S1201: After the user finds that the SIM is stolen, the user initiates a SIM re-registration operation.

S1202, the user resets the new SC, and then sends a SIM re-registration request and a new SC to the network side.

S1203: The network side regenerates the AC (SAC, MAC).

S1204: The network side updates the SC stored by itself using the received new SC.

S1205, the network side regenerates the KiM with the new AC (SAC, MAC) and the SC.

S1206: The network side regenerates the IMSI_M with the new AC (SAC, MAC) and the SC.

In S1207, the network side resets SUSE to an initial value of 1.

S1208: If all operations on the network side are successful, send a message that the SIM re-registration is successful to the user side, and send the new AC (SAC, MAC) to the user side; otherwise, send a message that the registration fails, and end the operation.

S1209: The user side determines the message sent back by the network side. If the SIM re-registration fails, the user is prompted to complete the operation; otherwise, the operation is continued.

S1210: The user side updates the saved AC (SAC, MAC) by using the new AC (SAC, MAC) sent by the network side.

S1211, the user side updates the SC.

S1212: The user side regenerates the KiM with the new AC (SAC, MAC) and the SC.

S1213: The user side regenerates the IMSI_M/MSIN_M with the new AC (SAC, MAC) and the SC.

In S1214, the user side resets SUSE to an initial value of 1.

S1215: After the foregoing operations are completed, the execution result is fed back to the user and the network side. The relevant data is saved on both sides.

The method and system for enhancing security of the SIM of the present invention provides a card rebinding operation for use when the user replaces the ME. The process is as shown, including:

S1301: The user initiates a card rebinding operation.

S1302, the SIM generates KiM in the manner of formula (3).

S1303: The user side encrypts the IMEI of the old and new MEs (represented by IMEI_new, IMEI_old) with KiM, and then sends them to the network side along with the machine card rebinding request and other related information.

S1304: After receiving the card rebinding request, the network side also generates KiM according to the formula (3).

S1305: The network side obtains IMEI_new and IMEI_old by using the newly generated KiM decryption.

S1306: The network side compares IMEI_old with the corresponding IMEI saved by itself.

S1307: Determine whether the old IMEI is the same as the previously registered IMEI, that is, whether the IMEI_old is the same as the IMEI. If they are the same, go to the next step; otherwise, the user is prompted with an error and ends the operation.

S1308, the network side registers the new ME and updates the records related thereto.

S1309: The network side generates an activation code SAC and MAC for the SIM and the new ME.

S1310: The network side updates the confidential data related to the SIM, including KiM, IMSI_M, etc., and then sends the SAC and the MAC along with the card rebinding success message to the user side.

S1311: The user side selects the next operation according to the type of the received message. If it is a rebinding success message, continue execution; otherwise, the user is notified and ends.

After receiving the machine card rebinding success message, the S1312 saves and updates related data, including: the ME saves the MAC, the SIM saves the SAC, the SIM updates the IMEI record, and regenerates the KiM, IMSI_M, and the like.

S1313, the operation result is fed back to each participant.

The above operations of the present invention and their embodiments may be used alone or in combination; some operations may be automatically performed by the system or manually by the user. Figure 14 shows an embodiment of the present invention on the user side, which is displayed in the form of a SIM application menu, which is initiated by the user.

The above embodiments are merely illustrative of the invention, and are not intended to limit the scope of the invention, and various modifications, alterations and variations can be made without departing from the spirit and scope of the invention. All equivalent technical solutions are also within the scope of the invention and should be defined by the claims.

The parts not described in the present invention are the same as those in the prior art.

Claims

A method for enhancing the security of the user identification module, including the following steps,

(1) Providing the following devices, a mobile communication network system, a mobile user terminal, and a subscriber identity module

(2) Checking the freshness of the subscriber identity module. When the subscriber identity module is installed in the mobile subscriber terminal for the first time to register in the network, the mobile communication network system queries the mobile communication network system for recording according to the relevant information of the subscriber identity module, and will The freshness check result of the one-time network registration is fed back to the user, and at the same time, the information related to the mobile user terminal used by the subscriber identity module to register the network is recorded.
The method for enhancing security of user identification module usage according to claim 1, further comprising the steps of:

(1) Generate an activation code. After passing the freshness check, two data are randomly generated by the network side of the mobile communication network system as an activation code and sent to the user side, one as an activation code of the user identification module and the other as a mobile user terminal. Activation code, each user identification module and the mobile user terminal where it is located have a corresponding activation code, and the network side saves the correspondence between the user identification module/mobile user terminal and the activation code for checking,

(2) Set the security code, the user sets a data as the security code of the user identification module, and sends it to the network side. Each SIM has a corresponding security code, and the network side saves the security code.
The method for enhancing security of user identification module according to claim 2, further comprising the steps of: generating an encryption key mask, and the network side performs the encryption key, the activation code, and the security code according to the following formula: The security combination encryption key mask = f (encryption key, user identification module activation code, mobile user terminal activation code, security code) is generated to generate an encryption key mask and replace the original encryption key, after which In the communication process, the encryption key is used instead of the encryption key for related authentication and encryption processing.
The method for enhancing security of user identification module according to claim 2, further comprising the steps of: generating an international mobile subscriber identification number mask, and the network side transmitting the international mobile subscriber identification number and the activation code and the security code. Perform the security combination International Mobile Subscriber ID mask as shown in the following formula = g (International Mobile Subscriber ID Mask, User Identification Module Activation Code, Mobile User Terminal Activation Code, Security Code) uses the actual international mobile subscriber identification number when registering for the first time, and then uses international mobile subscribers. The identification number mask replaces the real international mobile subscriber identification number.
The method for enhancing security of user identification module according to claim 1, further comprising the steps of: comparing a user identification module using a serial number, and the user identification module using the serial number for recording the number of times the user identification module is used in the network. When the user identification module is first initialized, the user side and the network side synchronously record and update the user identification module to use the serial number. When the user identification module enters the network authentication every time, the mobile communication network system compares the user side and the network side respectively. The saved user identification module uses the serial number to be consistent.