JPH01181181A - Ic card - Google Patents

Abstract

PURPOSE:To increase the security of data recording by outputting a signal to deny the existence of a data block and stopping the access of the corresponding data block when unjust access is judged. CONSTITUTION:The key collation of an accessing person is executed, the data block is designated only when in order and an access flag is set only at the time of the existence. At the time of the writing action of data, an access flag corresponding to the designated data block is read, when the flag is set, the same signal as that when the data block does not exist is outputted and when the flag is not set, the data are written, and a normal completing signal is outputted. At the time of reading data, the access flag corresponding to the designated data block is read, when the flag is set, the same signal as that when the data block does not exist, and when the flag is not set, the data are normally read and outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an IC card, and particularly to access control of recorded data thereof.

[Conventional technology]

An IC card has a built-in IC such as a CPU and memory, and has recently become popular.

Usually, an IC card is connected to a terminal (hereinafter referred to as an external device) of various application systems to convert data. Generally, an IC card interprets command data transmitted from an external device, executes the command data, and transmits the results to the external device as response data. Further, the data recorded on the IC card is managed in blocks, and accesses such as reading are also performed under management in units of blocks.

When a type of IC card is used in various application systems, data recording is performed independently for each block. A means is required to prevent recorded data of a block used by one system from being read by another application system, or from data being written to that block by another application system. One method is to record verification information in blocks on the IC card side and perform verification. Based on this matching result,
The IC card performs memory access control to permit access to each block.

If access to each block is not permitted, the IC card transmits response data indicating "access not permitted" to the external device.

However, 'access not permitted°' has a different meaning from 'the data block does not exist', and of course the former acknowledges the existence of the specified data block, for example, the definition of command data and response data. If a known unauthorized accessor uses an external device to gain unauthorized access, the presence of a block of internal data will be confirmed based on the content of the response, which poses a security problem for the data records on the card.

[Problem to be solved by the invention]

Conventional IC cards are configured as described above, so
There is a possibility that the existence of a block of internal data can be confirmed by an unauthorized person, which poses a problem in the security of data recording.

This invention was made to solve the above-mentioned problem. When an unauthorized accessor uses an external device to gain unauthorized access, the recording status of the data in the card is unclear from the contents of the card response. The purpose is to obtain a highly secure IC card.

[Means to solve the problem]

The IC card according to the first aspect of the present invention sets an access flag corresponding to each data block in a predetermined area in the memory, and sets or resets each access flag independently to access a specific data block. When doing so, the corresponding access flag is read, and if it is set, a response denying the existence of the designated data block is output, thereby prohibiting access to the designated data block.

Further, the IC card according to the second aspect of the present invention sets access authority information corresponding to each data block in a predetermined area in the memory, writes each access authority information, and when accessing a specific data block. , reads the corresponding access authority information, authenticates the access authority, outputs a response denying the existence of the specified data block if the authentication result is judged to be invalid, and prevents access to the specified data block. It was made to be prohibited.

[Effect]

In this invention, when accessing a data block, if unauthorized access is determined based on the corresponding access flag or access authority information, a signal denying the existence of the data block is output, and the corresponding data block is By stopping access to the block, the security of data recording can be increased without letting unauthorized accessors know the existence of the data block.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an example of an IC card according to the present invention. Further, FIGS. 2 and 3 are diagrams showing data blocks in the EEPROMIO of an IC card according to an embodiment of the present invention, and in these cases, each data block is divided into a directory 3 and a data recording portion 2,
An access flag 4 and access authority information 5 are set in the directory 3 corresponding to each data block. Each data block in these embodiments has access control information recorded in a corresponding directory, and can be specified by the logical identifier of the data block when accessed by an external device.

Next, the operation of the IC card according to the embodiment of the present invention will be explained.

4 to 7 are diagrams for explaining the embodiment in the case of FIG. 2.

FIG. 4 is an operation flowchart for setting an access flag. To set the access flag, first, a key verification check is performed on the accesser, and only if the data block is OK, the data block is specified, and the corresponding access flag is set only if the data block exists. FIG. 5 is an operation flowchart for resetting the access flag, and the operation access flag is reset in the same sequence as in FIG.

Further, FIG. 6 is an operational flowchart for writing data, in which a data block is designated and if it exists, the corresponding access flag is read. If the read access flag is set, the same signal as when the data block does not exist is output, and if it is not set, data is normally written to the specified block.
Outputs a signal indicating normal completion. Furthermore, FIG. 7 is an operation flowchart for reading data, in which a data block is specified in the same way as in FIG. Outputs the same signal as , and if it is not set, the data of the specified block is read and output normally.

In such an IC card, when an unauthorized person accesses the card using an external device, the same signal as when the data block does not exist is output in the response data, and the existence of the block is also acknowledged. Never.

8 to 13 are diagrams for explaining the embodiment in the case of FIG. 3.

FIG. 8 is an operation flowchart for writing access authority information. First, an access user key verification check is performed, and then
In the case of K, by specifying the data block, if the specified data block exists, any corresponding access authority information is written.

FIG. 9 is a diagram showing an example of this access authority information,
An accesser is defined corresponding to each bit, and “1”
Access is not possible until all access user authentication for a certain bit is completed. FIG. 11 is a flowchart showing an example of the operation for performing this accessor authentication. For example, when the card holder performs access user authentication, the access user designation and the entered secret tower number are verified. As a result of the verification, if it is determined to be valid, the corresponding flag in the accesser identification register is set.

FIG. 10 shows an example of the contents of the accesser identification register, and indicates that the accesser defined by the flag set to "1" has been successfully authenticated.

FIG. 12 is an operational flowchart for writing data into a data block. First, a data block is specified, and if the data block exists, the contents of the access user identification register and the contents of the corresponding access authority information are read out and compared.

If the matching is determined to be invalid, a data block is specified and the same signal as when the data block does not exist is output.

In the examples shown in FIGS. 9 and 10, each flag has a one-to-one correspondence, and verification can be performed by comparing two contents. In the example of FIG. 10, APO authentication has not yet been completed. Therefore, the verification result is determined to be invalid. This APO may be considered, for example, as a common access ID for each application system. In other words, even if only the principal has been verified, if the authentication on the application system side is not completed, it is determined that the data block corresponding to the card does not appear to exist in the card. Further, FIG. 13 is an operation flowchart for reading data from a data block, and in this case as well, the above-mentioned processing is performed in the same way as in the case of data writing.

Even in such an IC card, as in the embodiment shown in FIG. 2, the recording status of data in the card cannot be determined by an unauthorized accessor from the contents of the response data.

〔Effect of the invention〕

As described above, according to the IC card of the present invention, when accessing a data block, if unauthorized access is determined based on the corresponding access flag or access authority information, the existence of the data block is denied. Since a signal is output and access to the corresponding data block is prohibited, if an unauthorized accessor tries to access the data using an external device, the data in the card can be detected from the contents of the card-side response data. It is possible to prevent the recording status from being known, which has the effect of increasing security.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of an IC card according to the present invention, and FIG. 2 is a block diagram showing an example of an IC card according to the first embodiment of the present invention.
A diagram showing a data block of a card, FIG. 3 is a diagram showing a data block of an IC card according to an embodiment of the second invention of the present invention, and FIGS. 8 to 13 are diagrams for explaining the operation of the IC card according to the second embodiment of the present invention, respectively. 2 is a data recording portion of the data block, 3 is a directory of the data block, 4 is an access flag, 5 is access authority information, and 10 is a nonvolatile programmable memory. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (2)

[Claims] (1) An IC that has a built-in nonvolatile programmable memory and has data exchange means for exchanging data with the outside, data writing means for writing data into the memory, and data reading means for reading data from the memory.
In the card, a memory management means for managing the data in the memory in blocks and setting an access flag corresponding to each data block in a predetermined area in the memory, and means for independently setting or resetting each of the access flags. When accessing a specific data block, the corresponding access flag is read, and if it is set, the data exchange means outputs a response denying the existence of the specified data block, and the data exchange means outputs a response denying the existence of the specified data block. I characterized by comprising means for prohibiting access to
C card. (2) An IC that has a built-in nonvolatile programmable memory and has data exchange means for exchanging data with the outside, data writing means for writing data into the memory, and data reading means for reading data from the memory.
In the card, a memory management means for managing the data in the memory in blocks and setting access authority information corresponding to each data block in a predetermined area in the memory; a means for writing each of the access authority information; When accessing a data block, the corresponding access authority information is read, the access authority is authenticated, and if the authentication is determined to be invalid, a response denying the existence of the specified data block is sent to the above data. An IC card characterized by comprising: means for outputting the specified data block by the exchange means and prohibiting access to the specified data block.