JP3710863B2 - Mutual authentication system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a system that can perform mutual authentication in a system that uses an IC card or the like using an IC memory.
[0002]
[Prior art]
An IC card with a built-in CPU using an IC memory is excellent in security, and one of them is that mutual authentication can be performed. When using an IC card via a terminal, mutual authentication is performed by authenticating that the IC card is valid (terminal authentication) and authenticating that the IC card is valid (card By authenticating each other, an unauthorized device impersonated as an IC card or terminal is prevented from intervening.
Conventionally, in order to execute mutual authentication, for example, each of a card and a terminal needs to store both a card authentication key and a terminal authentication key. Therefore, conventionally, a master key for generating a card authentication key and a master key for generating a terminal authentication key are prepared separately, and these authentication keys are generated during card issuance processing and subsequent mutual authentication. It was.
[0003]
[Problems to be solved by the invention]
However, in a card system including at least such a card and a terminal, a single system may be used. However, in a system such as a prepaid IC card, the same type of system exists. It was necessary to manage individually so as not to overlap. Also, the conventional method has a problem that two types of master keys must be set and managed for each system.
[0004]
[Means for Solving the Problems]
Therefore, in order to solve the above-described problem, in the mutual authentication system of the present invention, two different authentication keys used in mutual authentication are not generated from different master keys, but are generated from the same master key. Easy management. In order to generate different authentication keys from the same master key, two types of authentication key generation algorithms are prepared. In order to obtain a different authentication key corresponding to each IC card, the card identification ID of each card is used as one of the parameters used by the generation algorithm.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The mutual authentication system of the present invention will be described below with reference to the drawings. The present invention is not limited to the relationship between the IC card and the terminal, but will be described assuming mutual authentication between the IC card and the terminal.
FIG. 1 is a conceptual diagram showing a relationship between each authentication key used for mutual authentication and a master key for generating them. The mutual authentication system of the present invention is basically a system composed of at least a first device (here, a terminal) and a second device (here, an IC card), and the first device is the first device. Keys required for the authentication of the two devices (here, card authentication) and the authentication of the second device with respect to the first device (here, terminal authentication), that is, the terminal authentication key And the same master key for generating the card authentication key.
In FIG. 1, a first device 10 (terminal) and a second device 20 (IC card) are devices that perform mutual authentication, and the first device 10 includes a master key 1 and is a centralized management system. is there.
[0006]
Further, in the system shown in the conceptual diagram of FIG. 1, the first device 10 includes a first authentication key generation algorithm 2 (terminal authentication key generation algorithm) and a second authentication key generation algorithm 3 (card authentication key generation algorithm). And comprising.
A second device authentication key 5 (card authentication key) used when the first device (terminal) authenticates each second device (IC card), and the second device authenticates the first device. The first device authentication key 4 (terminal authentication key) used in this case is generated in the second device (IC card) by the authentication key generation algorithm. The first device authentication key 4 (terminal authentication key) is generated by the first authentication key generation algorithm 2 (terminal authentication key generation algorithm), and the second device authentication key 5 (card authentication key) is the second It is generated by the authentication key generation algorithm 2 (card authentication key generation algorithm).
The second device (IC card) includes a device identification ID 6 (card ID) for identifying each device. The first and second authentication key generation algorithms 2 and 3 also use a device identification ID (card ID) for identifying each of the second devices (IC cards) in addition to the master key as an initial value. The first device authentication key 4 (terminal authentication key) and the second device authentication key 5 (card authentication key), which are different for each of the second devices, are generated.
[0007]
The second device may have two authentication keys provided in advance in the device prior to mutual authentication, but may receive key delivery from the first device during mutual authentication. For example, if the second device is an IC card, it receives key delivery from the card issuing device when it is issued.
[0008]
By adopting the system of the above form, it is sufficient to manage the same master key. In a system composed of a plurality of cards (second devices) and a plurality of terminals, a central device (considered as the first device) that integrates the terminals is managed with a single master key, or each terminal There may be a form in which the same master key is provided every time (in this case, this is regarded as the first device) (therefore, the same master key exists as many as the number of terminals).
[0009]
【Example】
Hereinafter, referring to the conceptual system configuration diagram of FIG. 2 and the flowcharts of FIGS. 3 and 4, as an embodiment of the mutual authentication system of the present invention, the procedure of mutual authentication in a system including an IC card and a terminal will be described. explain. FIG. 3 is a flowchart of terminal authentication, and FIG. 4 is a card authentication process.
[0010]
First, as shown in FIG. 2, in this embodiment, the terminal 30 incorporates a security module 40 in the terminal. The security module 40 always stores a master key (M) 41, and further calculates and generates a function g (x) and a card authentication key as a terminal authentication key generation algorithm 42 for calculating and generating a terminal authentication key. Generates a function h (x) as a card authentication key generation algorithm 43, an authentication function f (x) as an authentication algorithm 48 for performing arithmetic processing necessary for mutual authentication, and a random number (E) necessary for mutual authentication. A circuit for realizing a random number generation algorithm 49 is provided. The security module 40 is a component of the terminal.
The security module (hereinafter also referred to as “SM”) can be in the form of an IC card. A large number of terminals can be obtained by preparing a large number of the same security modules and setting them in each terminal. Is established.
[0011]
The IC card 50 is a bank card, a prepaid card, or the like depending on the application, and the card ID (A) 56 and the terminal authentication key (B) 54 differ from card to card. As the terminal authentication key (B) 54 and the card authentication key (C) 55 generated by the master key (M) 41 and the function g (x) 42 for calculating and generating the terminal authentication key, the card ID is also set when the card is initialized. (A) 56, the master key (M) 41, the card authentication key (C) 55 generated by the function h (x) 43 for calculating and generating the card authentication key, and the calculation processing necessary for mutual authentication. As an authentication algorithm 48 to be performed, a circuit for realizing an authentication function f (x) and a random number generation algorithm 49 for generating a random number (D) necessary for mutual authentication is provided. The card authentication function f (x) is the same as the terminal authentication function f (x). The card random number generation algorithm may be different from the terminal random number generation algorithm.
[0012]
Next, a terminal authentication processing procedure in which the IC card authenticates the terminal will be described with reference to FIG. In the figure, the numbers 11 to 30 indicate step numbers. First, terminal authentication starts with a request for sending a card ID of a terminal to an IC card (11: step number, and so on). Next, the IC card sends the card ID (A) to the terminal (12), the terminal transfers the received card ID to the SM (13), and the SM receives the card ID (A) (14). After receiving, the terminal issues a (terminal) authentication key calculation request to the SM (15). Upon receiving the calculation request, the SM receives the received card ID (A), the stored master key (M), A terminal authentication key (B ′) is calculated from the function g (x) and generated (16). Subsequently, the terminal issues a random number transmission request to the IC card (17), and in response, the IC card generates a random number (D) and sends it to the terminal (18), and the terminal receives the random number (D). (19), and the SM receives the random number (D) (20). Next, the terminal issues a (terminal) authentication calculation request to the IC card (21), and the IC card has the card ID (A) and the terminal authentication key (B) held by the IC card itself and the generated random number ( The function f (x), that is, the function f (A, B, D) is calculated using D) (22). Next, the terminal issues a (terminal) authentication calculation request to the SM (23), and the function using the card ID (A) received by the SM side, the generated terminal authentication key (B '), and the received random number (D). f (x), that is, the function f (A, B ', D) is calculated (24). Next, the terminal issues a calculation result transmission request to the SM (25). Upon receipt of the request, the SM transmits a function value f (A, B ', D) of the calculation result to the terminal (26), and the terminal receives the received calculation. The result is transferred to the IC card (27), and the IC card receives the function value f (A, B ', D) of the calculation result on the terminal side (28). Next, the terminal issues a calculation result comparison request to the IC card with respect to the calculation result of the IC card itself and the SM calculation result on the terminal side (29), and upon receiving the request, the IC card receives the function value f (A , B, D) and the function value f (A, B ′, D) are compared (30). If the comparison results match, the terminal is authenticated as the correct terminal of the system, and terminal authentication ends.
[0013]
Next, a card authentication processing procedure in which the terminal authenticates the IC card will be described with reference to FIG. In the same figure, the numbers 11 to 30 indicate step numbers. First, the card authentication starts with a request for sending the card ID of the terminal to the IC card (11: step number, and so on). Next, the IC card sends the card ID (A) to the terminal (12), the terminal transfers the received card ID to the SM (13), and the SM receives the card ID (A) (14). After receiving, the terminal issues a (card) authentication key calculation request to the SM (15). Upon receiving the calculation request, the SM receives the received card ID (A), the stored master key (M), A card authentication key (C ′) is calculated from the function h (x) and generated (16). Subsequently, the terminal issues a random number transmission request to the SM (17). In response to this, the SM generates a random number (E) and sends it to the terminal (18), and the terminal receives the random number (E) and receives the IC. The data is transferred to the card (19), and the IC card receives the random number (E) (20). Next, the terminal issues a (card) authentication calculation request to the SM (21), and the SM uses the received card ID (A), the generated authentication key (C '), and the generated random number (E) to generate a function f. (X), that is, the function f (A, C ′, E) is calculated (22). Next, the terminal issues a (card) authentication calculation request to the IC card (23), and the IC card itself also has a card ID and a card authentication key (C), and a random number (E) received by the IC card. Is used to calculate the function f (x), that is, the function f (A, C, E) (24). Next, the terminal issues a calculation result transmission request to the IC card (25). Upon receiving the request, the IC card transmits a function value f (A, C, E) of the calculation result to the terminal (26), and the terminal receives it. The calculation result is transferred to the SM (27), and the SM receives the function value f (A, C, E) of the calculation result (28). Next, the terminal issues a calculation result comparison request to the SM for the calculation result of the SM itself on the terminal side and the calculation result of the IC card (29), and upon receipt of the request, the SM receives the function value f (A, C, E) is compared with the function value f (A, C ′, E), and the result of whether or not they match is returned to the terminal (30). If the comparison results match, the IC card is authenticated as a correct IC card permitted by the system, and the card authentication ends.
[0014]
Note that the mutual authentication system of the present invention is not limited to the above embodiment, and may have various forms as described above, for example. For example, in the above embodiment, the same card ID (A) is used for the terminal authentication key and the card authentication key, but the card ID (A) and the card ID (A ′) Other values may be used. In this case, the IC card side has both the card ID (A) and the card ID (A ′) as card IDs. For example, a format in which the card ID (A) and the card ID (A ′) are separately stored in the card ID area as independent IDs, or a format in which part of the data of these IDs is overlapped and stored in the card ID area I own a card ID.
[0015]
【The invention's effect】
According to the mutual authentication system of the present invention, since the authentication key required for mutual authentication is generated with the same master key, it is only necessary to manage one type of master key for each system, and the master key can be easily managed. become. For example, even if there are a plurality of systems in a prepaid IC card system, it is only necessary to prepare a different type of master key for each system, and it is necessary to manage a plurality of master keys such as two types for each system. Since there are no master keys, the number of master keys to be managed is small, and the master keys can be easily managed.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of a mutual authentication system of the present invention.
FIG. 2 is a conceptual system configuration diagram of an IC card system which is an embodiment of a mutual authentication system of the present invention.
FIG. 3 is a flowchart of terminal authentication in the system of FIG. 2;
4 is a flowchart of card authentication in the system of FIG.
[Explanation of symbols]
1 Master key 2 First authentication key generation algorithm (terminal authentication key generation algorithm)
3 Second authentication key generation algorithm (card authentication key generation algorithm)
4 First device authentication key (terminal authentication key)
5 Second device authentication key (card authentication key)
6 Device identification ID (card ID)
7 Authentication algorithm (authentication function)
8 Random number generation means 10 First device (terminal)
20 Second device (IC card)
30 terminal 40 security module 41 master key 42 terminal authentication key generation algorithm, function g (x)
43 Card authentication key generation algorithm, function h (x)
48 Authentication algorithm, function f (x)
49 Random number generation algorithm 50 IC card 54 Terminal authentication key 55 Card authentication key 56 Card ID
58 Authentication algorithm 59 Random number generation algorithm

Claims (3)

In a mutual authentication system comprising at least a first device and a second device having a mutual authentication function,
The first device includes at least a master key, a first authentication key generation algorithm, and a second authentication key generation algorithm,
The second device comprises at least a device identification ID;
The second device authentication key used when the first device authenticates the second device includes a device identification ID of the second device, the master key, and a first authentication key generation algorithm. Generated using
The first device authentication key used when the second device authenticates the first device uses a device identification ID of the second device, the master key, and a second authentication key generation algorithm. Generated,
The mutual authentication system according to claim 1.   The mutual authentication system according to claim 1, wherein the second device is an IC card, and the first device is a terminal that accesses the IC card.   The mutual authentication system according to claim 2, wherein the IC card is a prepaid IC card.

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