KR100271782B1 - Role based authentication IC(Integrated Circuit) Card and Computer Security System Using the Same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer protection device that protects digital information of a computer and permits access to information only to authorized users. The present invention relates to a central processing unit, comprising a central authentication unit and a user computer. And an input / output unit, wherein the position authentication IC card measures a random number generation algorithm and a time from receiving a predetermined signal to receiving encrypted authentication data, and uses an authentication code corresponding to the time data as a key. An encryption algorithm for encrypting a random number, a data memory means for storing a table indicating a relationship between the authentication code and time data and a position code indicating a degree of data access authority of each user are provided. According to the present invention, a more economic and reliable protection device can be implemented.

Description

Title authentication IC card and computer protection device using the same {Role based authentication Integrated Circuit (IC) Card and Computer Security System Using the Same}

The present invention relates to a protection device for a computer, and more particularly, a title authentication IC card capable of preventing illegal intruders or personal computers from entering through a communication network and varying the degree of data access authority according to the user's position. And a computer protection device using the same.

Recently, with the development of information processing technology and communication technology, the rapid exchange of information using computer communication network and the majority of business processing using computer, digital data can be collected from unauthorized users or external intruders through computer communication network. There is an urgent need for a system that can be protected.

Therefore, researches are being actively conducted to transmit digital information only to a specific user and protect it from unauthorized users through a communication satellite, a local area network (LAN), or a communication network using a general telephone line. have. This computer information protection is a technology that is required by institutions that handle important information seriously not only by electronic commerce via the Internet, but also by an external intruder.

Conventionally, in order to protect computer information, a user ID code and password are set to check the user's permission and allow access to the computer information. The technology has also evolved and a number of external intrusions have been reported.

External intruders who access through computer networks can be protected by a fire-wall, but these firewalls are too expensive and disadvantageous in terms of economics.

Accordingly, an object of the present invention is to increase the security of a computer system by protecting computer digital information and allowing only authorized users to access the digital information.

It is still another object of the present invention to provide an IC card and a computer protection device using the same capable of protecting computer digital information at a lower cost.

1 is a schematic perspective view of a user computer in which the present invention is implemented;

2 is a block diagram of a position certification IC (Integrated Circuit) card suitable for use in a computer protection device according to the present invention;

3 is a block diagram showing a connection relationship between a job title IC card and a user computer according to the present invention;

4 is a table showing an authentication code stored in a data memory in a job title IC card according to the present invention and time data corresponding thereto;

5 is a flowchart showing the operation of the job title authentication IC card used in the authentication method according to the present invention;

6 is a flowchart illustrating the operation of a computer used in the authentication method according to the present invention.

<Description of Major Symbols in Drawing>

10; User computer 11; Display

12; Keyboard 14; LAN

20; Title certification IC card 21; CPU

22; Input / output unit 23; RAM

24; ROM 25; Data memory

26; Bus 27; timer

30; User 32; Host

The protection device according to the present invention for achieving the above object is (a) the input and output unit 22 for data input and output with the external element, (b) the CPU 21 is connected to the input and output unit, (c) the CPU RAM 23 for temporarily storing data necessary for arithmetic operations performed in (21), (d) ROM 24 for storing programs necessary for driving the CPU 21, (e) data memory 25 And (f) a title authentication IC card having a timer 27, wherein the data memory 25 is generated by the random number generation algorithm storage area 25a, the encryption algorithm storage area 25b, and the random number generation algorithm. An area 25c in which random numbers are stored, an area 25d in which a system key used by the encryption algorithm is stored, and an area 25e in which a table representing a relationship between a plurality of authentication codes and time data is stored ), Area 25f where job title codes are stored The timer 27 measures the time difference between the input time of the user ID and the password input time of the user, and the computer protection device using the job title authentication IC card includes (A) a random number generated from the job title authentication IC card ( R) means for receiving and generating encrypted authentication data based thereon; and (B) a time corresponding to an authentication code from the table stored in area 25e of data memory 25 of the title authentication IC card. Means for selecting data, (C) means for sending a count start signal to the position authentication IC card, and for resetting the timer 27, (D) authentication data generated by the means (A) and the position An authentication operation is performed based on the comparison result of the authentication data generated in the authentication IC card, which is stored in the position code stored in the area 25f of the data memory 25 of the position authentication IC card. And means for performing the authentication operation by varying the degree of data access authority.

The present invention will be described in detail with reference to the drawings.

1 is a schematic perspective view of a user computer in which the present invention is implemented. In general, the computer 10 may be configured in the form of a personal computer (PC) or a workstation (WorkStation), and includes an associated memory, a display device 11, a keyboard 12, and the like. The computer 10 is connected to another computer or a host computer through the communication network 18 to exchange necessary information.

The system processor and associated memory are mounted inside the body of the computer 10. The computer 10 also incorporates a floppy drive 13 and a CD drive 14 for use with auxiliary storage devices such as floppy diskettes and compact disks (CDs). The control panel 16 of the computer 10 includes a power switch, a reset switch, an operation indicator lamp, and the like, and a speaker 7 is an auxiliary device for outputting a voice signal.

The position protection IC card 20 for information protection according to the present invention is inserted into the card reader 15 so that the information of the position authentication IC card 20 can be read by the computer 10. The user authentication operation according to the present invention is performed by processing the information of the title authentication IC card 20 read by the card reader 15 in a system processor in the computer 10 or in a host system connected through a communication network 18. Is done.

On the other hand, once the card reader 15 is mounted on the computer 10, a person having a specific authority, for example, a person other than the system administrator arbitrarily disassembles the computer body, recognizes the information and stores the information stored in the job title authentication IC card 20. By erasing, information leakage due to theft of the job title authentication IC card 20 is prevented.

2 is a block diagram of a position authentication IC card according to the present invention. The position identification IC card 20 includes a CPU 21 (Central Process Unit), an input / output unit 22, a RAM 23 (Random Access Memory), a ROM 24 (Read Only Memory), a data memory 25 and a bus 26. bus). The input / output unit 22 controls data input and data output between the job title authentication IC card and an external device. The RAM 23 serves to temporarily store data necessary for operations or operations performed by the CPU 21. The ROM 24 is a read-only memory, which stores a program necessary for driving the CPU 21. The data memory 25 stores, for example, the user's ID code, ID code table, encryption algorithm, and general purpose data. The data memory 25 uses electrically erasable and programmable memory (EEPROM). The internal bus 26 connects each component of the job title IC card described above and transmits data.

The timer 27 is for measuring a time. The timer 27 measures a difference between an ID input time of a user and a password input time of a user, and starts a computer system when a password is input after a predetermined time delay after the user ID input. Restrict. In this way, when an illegal user attempts to access internal information using a stolen job title authentication IC card, the illegal user can be prevented from accessing the user by using the time taken to decrypt the password.

The position identification IC card 20 may have a one-chip structure in which the data memory 25 is manufactured on one chip with other components, and the data memory 25 is separated from the other components. It may have a multi-chip structure formed. The job title authentication IC card 20 operates as follows.

When a command is input to the input / output unit 22 from the outside, the CPU 21 executes a specific operation according to a program stored in the ROM 24. The result of the execution operation is also output to the outside via the input / output unit 22. The authentication operation of a party user according to the present invention goes through the same process.

Fig. 3 is a block diagram showing a connection relationship between a job title IC card and a user computer according to the present invention. The job title authentication IC card 20 is inserted into the card reader 15 included in the main body of the computer 10 of each user 30.

As described above, the computer 10 is operated by each user 30a-30e and authenticates whether each user has legitimate authority to use the computer system by the information stored in the inserted job title authentication IC card 20. Go through the procedure. The users 30 are connected to each other via a computer communication network, such as a LAN 14, and also to the host computer system 32. The random number generation algorithm is stored in the area 25a of the data memory 25 of the job title authentication IC card 20, and the encryption algorithm is stored in the area 25b. The encryption algorithm is a kind of signature algorithm, which generates a digital signature for each user. A digital signature is a bit string consisting of a plurality of bits.

An area 25c stores a random number generated by a random number generation algorithm, and an area 25d stores a system key used by an encryption algorithm. In the area 25e, a table indicating a relationship between the plurality of authentication codes and the time data is stored, and the time data is assigned to the plurality of authentication codes. The position code is stored in the area 25f, and data used for the general-purpose program is stored in the area 25g. The position code indicates the degree of data access authority of each user, and may be distinguished by different colors of the position authentication IC card 20 according to the position code. For example, the administrator of the system uses a blue card, the person in charge of digital information work green, and the general user uses a white card. The structure of the area 25e in which the authentication code is stored is as shown in FIG. The table consists of a time 42 and a key 44. The data TA, TB, TC, TD at time 42 are assigned to each authentication code of key 44. Data corresponding to the authentication code is obtained by using the authentication code as a key.

In FIG. 3, the computer 10 performs authentication using the job title authentication IC card 20. FIG. On the other hand, the computer 10 is connected to the LAN 14 to exchange data with other users 30a-30d or to the host 32. Of course, the computer 10 may be an independent personal computer, and when the user authentication is required, the present invention may be applied to an independent personal computer.

5 and 6 are flowcharts for explaining the authentication process according to the present invention performed between the title authentication IC card and a computer, FIG. 5 is a flowchart of operations performed on the title authentication IC card, and FIG. It is a flow chart of operations performed on a computer. These operations are performed by the CPU of the computer and the CPU of the title authentication IC card according to the authentication program stored in the ROM.

The position verification IC card 20 generates a random number R and sends it to the computer. The computer generates an encrypted authentication data f1 (R, S, key) based on an encryption algorithm, for example, an encryption algorithm function f1, and also using a desired authentication code and system key S, and generates the authentication data. Send to the authentication IC card. In the drawing, the authentication code is A, B, C,... Is shown.

The job title authentication IC card generates encrypted data f1 (R, S, key) based on the encryption algorithm function f1. The cipher data f1 (R, S, key) is the authentication data (key) stored in the area 25e of the data memory 25 of the position authentication IC card 20 and the system key (stored in the area 25d). From S). The title authentication IC card compares the cipher data with data already transmitted to the computer, that is, f` (R, S, key).

One embodiment of the present invention employs a special method when sending a desired authentication code away. For example, instead of sending the authentication code directly using something like a bungee signal, the authentication code is supplied using the time difference between commands.

5 and 6, the title authentication IC card generates a random number according to a random number generation algorithm stored in the area 25a of the data memory 25 (step 52), and transmits it to the computer (step 53). ). When a random number is received (step 72), the computer generates authentication data f1 (R, S, key) using the selected authentication code (step 73). The computer then selects the time data (TA, TB or TC) corresponding to the selection authentication code from the time table stored in the data memory. For example, if authentication code B is selected, time data TB is selected correspondingly (step 74).

Next, the computer sends a count start signal to the job title IC card to synchronize with the job title IC card (step 75) and resets the counter (step 76). The computer and the title verification IC card may have a timer circuit composed of separate hardware, or may have a counter operated by software of the CPU.

Similarly, the title authentication IC card resets the counter upon receiving the count start signal (step 55), the computer transmits the count start signal and then waits for a predetermined time set in the time table (steps 77, 78, and 79). The authentication data f1 (R, S, key) is transmitted to the position authentication IC card (step 80). The position authentication IC card receives the authentication data f1 (R, S, keys) from the time when the count start signal is received (steps 56, 57, 58), and stores the time table stored in the area 25e of the data memory 25. Count the time (steps 59, 60, 61, 62, 63 and 64) until obtaining the authentication code selected with reference.

The title authentication IC card calculates the encrypted authentication data f1 (R, S, key) from the selected authentication code (step 65), and compares it with the authentication data f1 (R, S, key) already received by the computer (step 66). , 67, 68). The job title IC card sends a comparison result signal to the computer indicating whether the two pieces of authentication data match (step 69).

Therefore, the authentication operation according to the present invention is performed without using the address where the authentication code is stored. As a result, the address where the authentication code is stored is not disclosed and a high security authentication operation is possible.

In the present invention, a one-time password technique is used. Since the information necessary for decryption of a password is not included in the ciphertext, the unconditional security that the ciphertext is not decrypted no matter how long it takes is very excellent.

In the present invention, an encryption scheme using a hash function is used. The basic concept is based on a digital signature scheme. The digital signature technique refers to a technique that verifies and verifies the signature of a user who accesses specific digital data to authenticate usage rights and then permits data access.

The most widely used digital signature scheme today is the RSA encryption scheme devised by Rivest, Shamit, and Adleman. According to the RSA technique, each user is given a secret key consisting of (P1, P2) and a public key consisting of (Q, r), where Q = P1 · P2, r is a positive integer), and the signature for some digital data M corresponds to the number x defined by x` = h (M) mod Q. Here, the function h means a hash function and maps a data string M to a k bit number (k = log Q). The hash function must first be easy to calculate h (M) given M, but it must be impossible to calculate M given h (M), and second, h (M) = h (M`). It must have two properties that it should be impossible to obtain two data strings M and M`.

The digital signature technique used in the present invention includes a random number generator for generating a random number for each user, a key generation algorithm for generating a secret and public key for each user, a signature algorithm for calculating a digital signature, and a digital signature. A verification algorithm for verification. Each component of this technique must operate in polynominal time, and at least random generators must be probabilistic. Each component also depends on a security parameter k, which determines the size of the random number, the size of the secret and public keys, and the amount of computation required to create the signature.

The random number generator assigns a secret random number R (I) to each user. Variable I is used to represent each user's ID. Random numbers are used to derive a secret key for a user using a key generation algorithm. The length of the random number is determined by k and the signature technique. In some cases, the value of R (I) can be calculated by the user. That is, each user can choose his own unique random number R (I). The key generation algorithm G takes as input the ID of each user who will generate the key, the value of R (I) and the authentication variable k. The output of the key generation algorithm consists of the public and secret keys for the user ID. Because the ID and public key are public, every user can access the other user's public key. Key generation algorithms are also disclosed, but each user can generate their own key because the random number used to generate the key is secret.

The signature algorithm takes as input the ID and secret key of each signing user, the message, and the index i of the message being signed. The index is i if the user used i-1 messages. The output of the signature algorithm is a bit string σ and a digital signature made by the signer for the message.

The attestation algorithm takes as input a message, public key, user ID and signature σ already signed. The output of the attestation algorithm may be invalid or valid, if for any message, user ID, index i, digital signature σ the output of the signature algorithm is equal to σ, then the output of the attestation algorithm is valid. In other words, the verification algorithm must recognize all valid signatures more accurately. The signature algorithm, verification algorithm, and key generation algorithm described so far depend on variable N, which represents an upper limit on the number of signatures calculated for all users. The above three algorithms also depend on variable B, which represents an upper limit on the number of bits signed so far using the system according to the invention.

In the signature scheme, the hash function h is used as part of the signature process. For example, the first step in signing message M in the RSA technique is to calculate h (M). For this technique to be secure, h must satisfy several properties. For example, a very important requirement is that the intruder should be unable to perform calculations to find a collision for h. The collision for h is a pair of strings M, M` that satisfy h (M) = h (M`). This is because the signature for message M using RSA or similar algorithm is determined only by h (M). If h (M) = h (M`), the attacker could construct a signature for M` by obtaining a valid signature for M, because the two strings have the same signature.

Any function from [0, 1] ^* to [0, 1] ^m (where m is a predetermined variable) can be a hash function. Usually a hash function is randomly chosen from a set of functions with a specific structure. For example, the ideal hash function here means a randomly taken function in all function spaces whose domain is [0, 1] ^* and the range is [0, 1] ^m . In other words, the ideal hash function is a function that assigns a random number of m bits to every string. So a hash function h is a function chosen randomly from the functions. m is usually equal to the authentication variable k.

An ideal hash function has a number of useful properties, for example, it is difficult to find collisions for an ideal hash function. In fact, it is possible to prove that an algorithm consisting of t steps to find a collision for the ideal h is unlikely to find a collision. In addition, the ideal hash function is difficult to invert. This is expressed in two ways: firstly, if M is an unknown random string of m bits and h (M) is given, then it is difficult to find M` that satisfies h (M) = h (M`), and secondly, Given a random string z, it is difficult to find M` that satisfies h (M`) = z. Finally, the ideal hash function is a good material for randomization. For example, h (00), h (01), h (10) and h (11) are all independent random strings within [0,1] ^m . Thus, h can be employed as a pseudo random generator.

According to the present invention, one can see how to use a hash function to create a digital signature. If the hash function is ideal, the signature scheme is 2 ^m-1 times safe. Increasing m to 100 or 200, for example, makes the signing technique safe from forgery and tampering. In addition, each public key consists of m bits, each signature consists of thousands of bits, and the signature process consists of hashing thousands of data bytes. Most hash functionalization is done in advance in off-line format. The verification process also consists of hashing M along thousands of bytes of data.

This public key encryption algorithm is applied to both one-way and two-way authentication. One-way authentication is where a user is granted permission to use a host system, and two-way authentication is a required procedure between each user who is intangibly connected through a network. For one-way authentication, the protocol generates a random number and sends it to the user, who then encrypts it with his private key and returns it back to the host. The host decrypts the information sent by the user with the public key and authenticates the user if it matches the random number generated by the host.

Although the embodiments of the present invention have been described with reference to the drawings, it is possible for those skilled in the art to which the present invention pertains to various embodiments that are not shown in the drawings without departing from the spirit of the present invention. It will be easy to understand.

As described above, according to the present invention, since digital information transmitted through a computer communication network or the like is accessed by a user through a process of authenticating whether there is a legitimate user right, the security of digital information can be improved.

Claims (9)

A device that protects a computer using a job title IC card. A device that protects a computer using a job title IC card. The position identification IC card includes (a) an input / output unit 22 for data input / output with an external element, (b) a CPU 21 connected to the input / output unit, and (c) an operation performed by the CPU 21. RAM (23) for temporarily storing data necessary for operation, (d) ROM (24), (e) data memory (25), and (f) timer (27) for storing programs for driving the CPU (21). ), The data memory 25 includes a random number generation algorithm storage area 25a, an encryption algorithm storage area 25b, an area 25c in which a random number generated by the random number generation algorithm is stored, and a system key used by the encryption algorithm. an area 25d in which a system kye is stored, an area 25e in which a table indicating a relationship between a plurality of authentication codes and time data is stored, and an area 25f in which a job code is stored, The timer 27 measures the time difference between the input time of the user ID and the password input time of the user, The computer protection device using the position certification IC card, (A) means for receiving a random number (R) generated from the position authentication IC card and generating encrypted authentication data based thereon; (B) means for selecting time data corresponding to an authentication code from the table stored in an area 25e of the data memory 25 of the position authentication IC card; (C) means for sending a count start signal to the position authentication IC card and resetting the timer 27; (D) An authentication operation is performed based on a comparison result of the authentication data generated by the means (A) and the authentication data generated in the title authentication IC card, wherein the area of the data memory 25 of the title authentication IC card is performed. Means for performing an authentication operation by varying the degree of data access authority according to the position code stored in (25f). A computer protection device using a job identification IC card, characterized in that it is provided. The apparatus of claim 1, wherein starting of the computer is restricted when the time difference measured by the timer is greater than a predetermined time value. 2. The computer protection system of claim 1, further comprising a card reader capable of reading information stored in the job title authentication IC card through the input / output unit 22 of the job title authentication IC card. Device. And the computer includes a plurality of user computers and a host computer, wherein the plurality of user computers are connected to each other via a communication network and also to the host computer. The method of claim 1, wherein the authentication code is h (M) mod Q for the digital data M, where h (M) is a hash function for M, Q is a secret key (P1, A computer protection device using a title authentication IC card, which is a product of P2), that is, a digital signature defined by P1 and P2). The computer protection apparatus of claim 1, wherein the authentication code uses a random number generated by the random number generation algorithm using a user ID input through an input / output unit of a user computer. The position authentication IC card of claim 1, wherein the random number generation algorithm and the encryption algorithm rely on an authentication variable that determines the size of the random number, the size of the secret and public keys granted to the user, and the amount of computation required for encryption. Computer protection device using a computer. As an IC card, (a) an input / output unit 22 for inputting / outputting data with an external device, (b) a CPU 21 connected to the input / output unit 22, (c) RAM 23 for temporarily storing data necessary for arithmetic operations performed by the CPU 21, (d) a ROM 24 in which a program necessary for driving the CPU 21 is stored, (e) data memory 25 and (f) having a timer 27, The data memory 25 includes a random number generation algorithm storage area 25a, an encryption algorithm storage area 25b, an area 25c in which a random number generated by the random number generation algorithm is stored, and a system key used by the encryption algorithm. an area 25d in which a system key is stored, an area 25e in which a table indicating a relationship between a plurality of authentication codes and time data is stored, and an area 25 (f) in which a job code is stored, The timer 27 measures the time difference between the input time of the user ID and the password input time of the user. IC card, characterized in that. 9. An IC card according to claim 8, characterized in that it has a posi that is distinguished from each other according to a position code stored in an area (25f) of the data memory (25).

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