JP3564899B2 - IC card and IC card system - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an IC card capable of performing authentication such as whether or not the user is an authorized user of the IC card by using image data or the like.
[0002]
[Prior art]
As a conventional IC card, there is an IC card having a built-in EEPROM having a storage capacity of 500 bytes, 1 KB, 2 KB, 4 KB, 8 KB, 16 KB or 32 KB. This storage capacity is smaller than other storage media such as SRAM, DRAM, FRAM (first page RAM) or flash memory. In addition, since the conventional IC card usually has eight external communication terminals, half-duplex communication is generally adopted as the communication method.
[0003]
Further, in the conventional IC card, when a large amount of data is used as authentication data, the authentication data is compressed in a higher-level device which is a communication source of the data and a communication partner of the IC card. Thus, the amount of information is reduced and stored in the IC card.
[0004]
[Problems to be solved by the invention]
By the way, in the conventional IC card, the storage capacity of the built-in EEPROM is only 32 Kbytes at the maximum, and it is a slow communication method called half-duplex communication. For this reason, when the host device uses image data such as a face photograph, fingerprint, or retina as authentication data, a large amount of the authentication image data cannot be captured in the IC card. Thus, there is a problem that the IC card cannot be used in the host device.
[0005]
Further, when image data is used as data for authentication of an IC card, it is necessary to reduce the amount of data by thinning out the authentication image data in the host device or making the scan interval rough when inputting an image. there were. As a result, the image data becomes coarse.
[0006]
Furthermore, there is a problem in a method of compressing image data using a conventional general data compression method such as a run-length method or a Huffman method. The image data compressed by these compression methods can be decompressed by a third party other than the authorized user of the IC card. As a result, it is conceivable that a third party may use the authentication data illegally, and there is a security problem.
[0007]
The present invention has been made under such a background, and it is an object of the present invention to provide an IC card which can use a large amount of data such as image data as data for authentication such as identity verification and has high security. With the goal.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 includes a memory capable of rewriting information, and a central processing unit that controls an operation of the IC card based on a program stored in the memory. A command including data to be authenticated is externally received, the data is divided into blocks, and the command is compressed by referring to the command identification information included in the command. Receiving means for determining whether or not the command is a command; and, when the receiving means determines that the command is a compressed command, compressing the data for each block to form authentication data and storing the data in the memory. Means.
[0009]
According to a second aspect of the present invention, in the IC card according to the first aspect, the compression command includes compression specification information indicating designation of table processing or record order processing with respect to compression. Refers to the compression regulation information when performing the compression, and if the table processing is specified, refers to a table in which record numbers are randomly arranged in advance, and records that are randomly arranged in the table. Numbers are sequentially read, and blocks of data corresponding to each record number are sequentially compressed and stored as authentication data in the memory. On the other hand, when processing in the record order is specified, the record of the data is deleted. In this order, corresponding blocks of data are sequentially compressed and stored as authentication data in the memory. To have.
[0010]
According to a third aspect of the present invention, there is provided an IC card comprising: a memory capable of rewriting information ; and a central processing unit for controlling an operation of the IC card based on a program stored in the memory. A command including data to be processed is received from the outside, the data is divided into blocks, and whether or not the command is an authentication command is determined by referring to command identification information included in the command. receiving means for the compression means for storing when the command is determined to be authenticated command by the receiving unit, the data after the compression to authentication data for each block in the memory, included in the command By referring to the authentication information, it is determined whether or not the authentication processing should be performed in the IC card. If it is determined that it should authentication processing at an internal, collates the authentication data compressed by the compression means to receive from outside of the memory in compressed authentication data and the IC card that is stored Authentication means for performing authentication.
[0011]
According to a fourth aspect of the present invention, in the IC card according to the third aspect, when the authentication unit determines that authentication processing should not be performed in the IC card as a result of referring to the authentication information, The authentication data compressed by the means is transmitted to the outside which is the transmission source of the command.
[0012]
According to a fifth aspect of the present invention, there is provided an IC having the IC card according to any one of the first to fourth aspects and an external device that is a source of the command to be communicated with the IC card. A card system, wherein the external device receives the authentication data generated by the compression means of the IC card from the IC card, and the received authentication data and the authentication data already registered in the external device. It is characterized in that the IC card is authenticated by collating the authentication data with the authentication data.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
A: Configuration of Embodiment FIG. 1 is a block diagram showing a configuration of an IC card according to an embodiment of the present invention. Here, the EEPROM 4 is a nonvolatile memory that stores data in a rewritable manner. The ROM 2 is a non-volatile memory that stores a program that defines the operation of the IC card 10. Note that a program that defines the operation of the IC card 10 may be stored in the EEPROM 4. The RAM 3 is a volatile memory that temporarily stores data. The CPU 1 controls the operation of the IC card 10 based on a program stored in the ROM 2. The coprocessor 5 is a control device that assists the operation of the CPU 1.
[0016]
The coprocessor 5 includes a receiving unit 5a, a compressing unit 5b, a reproducing unit 5c, a table operating unit 5d, and an authentication unit 5e. Here, the receiving unit 5a receives data to be authenticated for the IC card 10 from outside. The reception is performed by dividing the data to be authenticated into blocks each having a data amount smaller than a predetermined amount and storing the blocks in the RAM 3 for each block. This block may be, for example, data represented by 64 bytes as one block. The compression unit 5b continuously compresses the data to be authenticated stored in the reception unit 5a for each block. Then, the compression means 5b stores the compressed authentication data in the EEPROM 4. Using the authentication data stored in the EEPROM 4 and a predetermined key, the reproducing unit 5c reproduces the authentication data into data before compression. The table operation unit 5d arranges each authentication data for each block compressed by the compression unit 5b using a table, and changes each arrangement under a predetermined condition. The authentication unit 5e performs authentication by comparing the authentication data received from outside the IC card 10 with the authentication data reproduced by the reproduction unit 5c for each block.
[0017]
It is preferable that the data compression in the compression unit 5b is performed using, for example, a one-way hash function. The one-way hash function is a compression function h that does not easily cause collision. Here, the collision means that h (x ₁ ) = h (x ₂ ) for different x ₁ and x ₂ . The compression function is a function for converting a bit string having an arbitrary bit length into a bit string having a certain length. Therefore, the one-way hash function is a function h (x) for converting a bit string of an arbitrary length into a bit string of a certain length _, and easily converts x _{1 and} x ₂ satisfying h (x ₁ ) = h (x ₂ ). (In terms of polynomial complexity). At this time, x that satisfies y = h (x) cannot be easily found from arbitrary y, so that it necessarily becomes a one-way function. As this one-way hash function, for example, an existing function such as MD4, MD5, SHA or SHA-1 (a standard draft of a one-way hash function of NIST in the United States) can be used.
[0018]
B: Operation of Embodiment Next, the operation of the IC card 10 having the above configuration will be described.
FIG. 2 is a flowchart showing the command processing in the IC card 10. Commands for the IC card 10 include a data compression command and an authentication command. First, when receiving a command from a higher-level device, the receiving unit 5a checks whether the data compression flag of the command is “0” (S1). The data compression flag is a flag indicating whether or not a data compression command is being executed, and is cleared to “0” at the time of reset.
[0019]
If the data compression flag is "0", an initial value "1" is set in the register R0 holding the record number, and a table address is set in the register R1 (S2). Thereby, the initial setting for the data compression command is performed. On the other hand, if the data compression flag is not “0”, the data compression process is being executed, and the process of step 2 is not performed.
[0020]
Thereafter, the receiving means 5a determines whether the received command is a compressed command (S3). In this determination, as in the case of the compressed command shown in FIG. 7, when P1 in the command is “00H”, it is determined that the command is a compressed command. If it is determined that the command is a compression command, the data compression flag is set to "1" (S4). Then, the compression unit 5b performs data compression (S5).
[0021]
On the other hand, if it is determined in step 3 that the received command is not a compressed command, the receiving unit 5a determines whether the received command is an authentication command (S6). If it is determined that the command is an authentication command, the receiving unit 5a determines whether the data compression flag is “0”. If the data compression flag is "0", the authentication means 5e executes data authentication (S8). On the other hand, if it is determined in step 6 that the command is not an authentication command, or if it is determined in step 7 that the data compression flag is not “0”, the process for the error status is performed (S9).
[0022]
FIG. 3 is a flowchart showing the data compression (S5) processing in FIG. 2 in detail. First, the compression unit 5b determines whether or not the record number held in the register R0 is smaller than a predetermined number of records (S11). Here, when the value of the record number is smaller than the number of records, the compression means 5b stores the data to be compressed in the address on the EEPROM 4 indicated by the register R0 (S12). This data may be stored in the RAM 3. Then, the compression unit 5b performs a compression process (S13). Further, the compression means 5b stores the compressed data in the EEPROM 4 as authentication data (S14). Thereafter, the compression means 5b adds "1" to the value of the register R0 (S15), and ends the data compression processing of one block.
[0023]
On the other hand, if the record number held in the register R0 is equal to or greater than the number of records in step 11, the compression means 5b enters an error status and returns an EOF indicating the end of the file to the host device (S16). Then, the compression unit 5b sets the data compression flag to “0” (S17), and ends the data compression processing.
[0024]
Thus, in the embodiment shown in FIG. 3, since the data compression processing is performed for each record, that is, for each block, the work area for the data compression processing can be reduced, and the storage capacity of the EEPROM 4 and the RAM 3 is reduced. be able to.
[0025]
C: Modified Example FIG. 4 is a modification of the compression process (S13) in FIG. 3, and is a flowchart showing the modification in detail. First, the compression unit 5b determines whether a table process is specified in the compression command or a process in record order is specified (S21). Here, in the format of the compressed command shown in FIG. 7, when P2 is "00H", table processing is specified, and when P2 is "01H", processing in record order is specified. Further, the table processing refers to performing a so-called table operation of arranging each authentication data for each compressed block using a table and changing the arrangement under predetermined conditions. The processing in the record order means that the subsequent processing proceeds in the same order as when the compression processing was performed for each block.
[0026]
If it is determined in step S21 that the table processing is designated, the table operating means 5d first determines whether the value of the register R2 is equal to or smaller than the number of records (S22). Here, when the value of the register R2 is equal to or less than the number of records, the contents of the address (record number) of the register R1 are set in the register R0. Further, "1" is added to the contents of the register R1 and "1" is added to the contents of the register R2 (S23).
[0027]
Thereafter, the compression means 5b reads out the data of the record number held in the register R0 (S24) and performs a compression process (S25). Then, the compressed data is stored as authentication data (S26). Further, "1" is added to the contents of the register R0 (S27).
[0028]
On the other hand, if it is determined in step 21 that the processing is in the order of records, first, the compression unit 5b determines whether the value of the register R0 is equal to or less than the number of records (S28). If the value of the register R0 is equal to or smaller than the number of records, the process proceeds to step S24. On the other hand, if the value of the register R0 is larger than the number of records, the compression unit 5b enters an error status and returns EOF indicating the end of the file to the host device (S29).
[0029]
As a result, in the embodiment shown in FIG. 4, since the arrangement of each authentication data on the EEPROM 4 becomes random by operating the table, it becomes more difficult for a third party to decompress the compressed authentication data. , Security can be improved.
[0030]
FIG. 5 is a flowchart showing the data authentication (S8) in FIG. 2 in detail. First, the receiving unit 5a receives data to be authenticated from the host device for each predetermined block. Then, the compression unit 5b performs compression processing on the data received in the procedure shown in FIGS. 3 and 4 for each block (S31). The reception and compression processes are repeated until the end of the file (EOF) is reached (S32).
[0031]
Next, the authentication unit 5e determines whether or not card authentication is performed (S33). In this determination, as in the authentication command (card authentication) shown in FIG. 7, when P1 in the command is "01H", it is determined that the command is a card authentication command. If it is determined that the command is a card authentication command, the authentication unit 5e performs an authentication process (S34). That is, the authentication data compressed in step 31 is compared with the authentication data already stored in the EEPROM 4 to determine whether the two are the same. Here, if they are the same, it means that the user of the IC card has been authenticated as a valid right holder. After that, the authentication unit 5e sets the status (S35) and returns the authentication result to the host device.
[0032]
On the other hand, if it is determined in step 33 that the authentication is not card authentication, the authentication data compressed in step 31 is set in the EEPROM 4 (S36). Then, the authentication unit 5e sets the status (S35), and transmits the compressed authentication data to the host device.
[0033]
Thus, in the embodiment shown in FIG. 5, the authentication data is generated based on the image data, and the authentication data is generated and the authentication process is performed inside the IC card. Can be authenticated without outputting to the outside, and security can be further improved.
[0034]
FIG. 6 is an explanatory diagram showing the file structure of the authentication data according to the present embodiment. Here, as the directory structure, first, the head address of the data file and the number of records which is a predetermined value are stored. After the number of records, the authentication table address and the number of records in the authentication table are stored, and then the authentication data is stored. Note that the figure shows that there are 128 records.
[0035]
On the other hand, the number of the record to be authenticated is recorded in the authentication table. As shown in the figure, the record numbers are randomly arranged on the authentication table. As a result, it becomes more difficult for a third party to decrypt the authentication data, and the security is further improved.
[0036]
FIG. 7 is an explanatory diagram showing a command format of the IC card in the present embodiment. Here, INS is data for identifying a compression command or an authentication command. In the compression command, INS is 43H, and in the authentication command, INS is 56H. P1 is data for identifying whether or not to perform authentication processing in the IC card. When P1 is 00H, only authentication data is created, and when P1 is 01H, authentication data creation and authentication processing are performed. P2 is data indicating whether or not to perform table processing. When P2 is 00H, table processing is performed, and when P2 is 01H, record order processing is performed without table processing. Le is data indicating the expected length of the authentication data. The compression command contains data to be compressed. In the figure, data that can be represented by 64 bytes is data to be compressed for one record (one block). On the other hand, the authentication command includes authentication data.
[0037]
In the above-described embodiment, the authentication processing is performed in the IC card. However, the present invention is not limited to this, and the authentication processing may be performed in the host device. Specifically, first, the authentication data generated by the compression processing in the IC card 10 is transmitted to the host device. Then, in the host device, the authentication is performed by comparing the already registered authentication data with the authentication data received from the IC card.
[0038]
Further, in the above-described embodiment, the data subjected to the compression processing is used as the authentication data. However, the present invention is not limited to this. For example, the authentication data may be used by using the compressed data and a predetermined key. A means for reproducing data before compression may be provided.
[0039]
As a result, in the present embodiment, the compression algorithm can be stored only in the IC card, so that it is almost impossible for a third party to falsify or falsify the authentication data, and an IC with high security Cards can be provided.
[0040]
【The invention's effect】
As described above, according to the present invention, the data to be authenticated is divided into small blocks each of which is quantitatively received and received from the outside, and is successively compressed for each block. Thus, the amount of memory used in the IC card can be reduced, and relatively large data such as image data can be used as authentication data. Therefore, an IC card having high security can be provided.
[0041]
Further, in the data compression processing according to the present invention, if a one-way hash function is used, it becomes very difficult to restore the compressed authentication data, so that the security can be further improved.
[0042]
In the generation of the authentication data according to the present invention, the address of each authentication data for each compressed block is rearranged at random using a table, so that a third party can further restore the authentication data. And security can be further improved.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an IC card according to an embodiment of the present invention.
FIG. 2 is a flowchart illustrating a command process in the embodiment.
FIG. 3 is a flowchart showing a data compression procedure in the embodiment.
FIG. 4 is a flowchart showing details of a main part of the data compression procedure shown in FIG. 3;
FIG. 5 is a flowchart showing a data authentication procedure in the embodiment.
FIG. 6 is an explanatory diagram showing a file structure of authentication required data in the embodiment.
FIG. 7 is an explanatory diagram showing a command format of the IC card in the embodiment.
[Explanation of symbols]
1 CPU
2 ROM
3 RAM
4 EEPROM
5 coprocessor 5a receiving means 5b compression means 5c reproducing means 5d table operating means 5e authentication means 10 IC card

Claims (5)

An IC card comprising: a memory capable of rewriting information; and a central processing unit that controls an operation of the IC card based on a program stored in the memory.
A command including data to be authenticated is externally received, the data is divided into blocks, and by referring to command identification information included in the command, whether or not the command is a compressed command is determined. A receiving unit for determining, and when the receiving unit determines that the command is a compressed command, a compressing unit for compressing the data block by block and storing the compressed data as authentication data in the memory. Characteristic IC card. The compression command includes compression specification information indicating the specification of table processing or the processing of record order with respect to compression,
The compression unit refers to the compression regulation information when performing the compression, and refers to a table in which record numbers are randomly arranged in advance when the table processing is designated, and randomly arranges the table in the table. Are sequentially read, and blocks of data corresponding to each record number are sequentially compressed and stored as authentication data in the memory. On the other hand, when processing in the record order is specified, the data 2. The IC card according to claim 1, wherein the corresponding data blocks are sequentially compressed as authentication data and stored in the memory in the order of the records. An IC card comprising: a memory capable of rewriting information; and a central processing unit that controls an operation of the IC card based on a program stored in the memory.
A command including data to be authenticated is externally received, the data is divided into blocks, and by referring to command identification information included in the command, whether or not the command is an authentication command is determined. Receiving means for determining ,
When the receiving unit determines that the command is an authentication command, the compression unit stores the data in the memory after compressing the data for each block as authentication data;
By referring to the authentication information included in the command, it is determined whether or not the authentication processing should be performed in the IC card. When it is determined that the authentication processing should be performed in the IC card, An authentication unit for performing authentication by comparing the compressed authentication data stored in the memory with the authentication data received from the outside of the IC card and compressed by the compression unit. IC card. If the authentication unit determines that authentication processing should not be performed in the IC card as a result of referring to the authentication information, the authentication unit transmits the authentication data compressed by the compression unit to the external device that is the transmission source of the command. The IC card according to claim 3, wherein An IC card system comprising the IC card according to any one of claims 1 to 4, and an external device that is a source of the command to be communicated with the IC card,
The external device includes:
By receiving the authentication data generated by the compression unit of the IC card from the IC card and comparing the received authentication data with the authentication data already registered in the external device, An IC card system for authenticating the IC card.

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