JPS63211049A - Portable electronic equipment - Google Patents

Abstract

PURPOSE:To improve security property by setting ciphering and decoding algorithm programs at every area of the data memory in an IC card. CONSTITUTION:A data memory 12 is divided to plural areas, and leading addresses, area sizes, and area peculiar information of these areas the stored in an area (00), and leading addresses of ciphering and decoding algorithm programs are stored in an area (01) correspondingly to respective area peculiar information. When a write instruction is inputted, a control element 11 finds the write objective area and area peculiar information in the area (00) and writes data based on the leading address of the corresponding encipherment algorithm program in the area (01). In the case of read, the decoding algorithm program is executed to read out data. Thus, the security is improved.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention is applicable to non-volatile data memory and CPU
The present invention relates to a portable electronic device called an IC card, which has a built-in IC (integrated circuit) chip having a control wJ element such as a control device.

(Prior Art) Recently, an IC card containing a built-in IC chip having a nonvolatile data memory and a control element such as a CPU has been used as a new portable data storage medium. This type of IC card accesses a built-in data memory using a built-in control element, and performs input/output of necessary data in response to a request from an external device. Further, the data memory is divided into a plurality of areas, and the target areas can be accessed selectively.

Now, with such an IC card, when writing data to the data memory, the data is encrypted before writing, and when reading data from the data memory and outputting it to the outside, the read data is decrypted first. It may be output externally. However, conventionally, this encryption/decryption process has been performed using a single pair of encryption/decryption algorithms. For this reason, the encryption/decryption algorithm pair is easily deciphered, and if it is deciphered, it becomes impossible to protect the data if it is read out illegally, resulting in a problem that the security of the system is poor.

(Problems to be Solved by the Invention) As described above, the present invention performs encryption/decryption processing using a single encryption/decryption algorithm pair. This was done in order to solve the problem that if the data were to be decrypted, it would be impossible to protect the data when it was read out illegally, and the system would have poor security. The purpose of the present invention is to provide a portable electronic device that is difficult to decipher, enables data protection when the data is read out illegally, and allows construction of a system with low security.

[Structure of the Invention] (Means for Solving the Problems) The present invention has a data memory section and a control section for reading and writing data to the data memory section, and selectively controls external In a portable electronic device that performs input/output from a computer, a plurality of encryption/No. A feature is that the encryption/decryption algorithm pair for encrypting and decrypting data during writing and data reading is determined for each area.

(Function) Since the encryption/decryption algorithm pair for data writing and data reading can be assigned to each area of the data memory section, the encryption/decryption algorithm pair may be decrypted and the data may be illegally stolen. It becomes possible to protect data when it is read, and a system with high security can be constructed.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 9 shows an example of the configuration of a card handling device used as a terminal device in a financial system or a shopping system, to which an IC card as a portable electronic device according to the present invention is applied. That is, this device allows an IC card 1 to be connected to a control unit 3 consisting of a CPU or the like via a card reader/writer 2, and also connects a keyboard 4 to the control unit 3. It is constructed by connecting a CRT display device 5, a printer 6, and a floppy disk device t7.

FIG. 8 shows an example of the configuration of the IC card 1, which includes a tlIII element (for example, a CPU) 11 as a control part, a nonvolatile data memory 12 whose storage contents can be erased as a data memory part, and a program memory part as a program memory part. It is composed of a program memory 13, and a contact part 14 for obtaining electrical contact with the card reader/writer 2, of which the part within the broken line (the control element 11,
data memory 12, program memory 13) is one I
It is composed of a C chip and is embedded within the IC card body. The program memory 13 is composed of, for example, a mask ROM, and as shown in FIG. B.

・・・・・・Decoding algorithm program A ' a B '#・・・・・・ Which is paired with these respectively.
It is something to remember. The data memory 12 is used to store various data, and is composed of, for example, an EEFROM.

The data memory 12 is divided into a plurality of areas, as shown in FIG. 3, for example, and each area is given an area number [00, 01, . . . Among these, area [00] includes area [02, 03,...
], the area size (the number of bytes constituting the area), and area-specific information (specific information) are stored in correspondence with the area number. For example, the start address of area [02] is aaall, the area size is Sa bytes, and the area specific information is B. Also, in area [01], there is a second
As shown in the figure, area-specific information and the start address of the corresponding encryption/decryption algorithm pair program are stored in association with each other.

For example, the start address of the encryption algorithm block corresponding to the area specific information A corresponds to the xaa address, and the start address of the decryption algorithm block corresponds to the xaa' address.

The area-specific information determines which encryption/decryption algorithm pair program is to be used when there is a data write/data read request from the card reader/writer 2. For example, in FIG. 3, when writing to area [02], encryption algorithm program B is written, and in area [03], encryption algorithm program C is written.
A is used in each area [04]. Further, when reading is performed on area [02], decoding algorithm program B' is used, C' is used in area [03], and A' is used in area [04].

Next, the operation in such a configuration will be explained.

First, the data write operation will be explained with reference to the flowchart shown in FIG. The IC card 1 is in a state where it has command data from the card reader/writer 2 in a steady state. In this state, when write command data having a format as shown in FIG. The write target area number is entered starting from area [00j] of the data memory 12. If you can't find it, lll
The 11Il element 11 outputs response data indicating that the area is unconfirmed to the card reader/writer 2, and returns to the command data holding state again. If found, the 6111 element 11 recognizes the designated write target area of the data memory 12 based on the start address and area size of the area stored in correspondence therewith. At this time, the w4m element 11 further refers to the corresponding area-specific information, and outputs the referenced area-specific information from area [01] of the data memory 12. Then, the control element 11 tlMs the start address of the encryption algorithm program stored correspondingly, executes the corresponding FRH algorithm program, encrypts the write data included in the write command data, and stores the data in the data memory. Write to 12 write target areas. When the writing is completed, the control element 11 sends response data indicating the completion of writing to the card reader/writer 2.
and returns to the instruction data waiting state.

Next, the data read operation will be explained with reference to the flowchart shown in FIG. The IC card 1 is in a state where it has command data from the card reader/writer 2 in a steady state. In this state, when read command data having a format as shown in FIG. 7 is input from the card reader/writer 2, the reader 11 decodes this read command data and includes The included read target area number is indexed from area [00] of the data memory 12. If it is not found, the control element 11 outputs response data indicating that the area has not been confirmed to the card reader/writer 2, and returns to the command data holding state again. If found, the control element 11 refers to the specified read target area of the data memory 12 based on the start address and area size of the area stored in correspondence therewith, and reads and stores the data in that area. R.A.
Temporarily hold in M. Next, the control element 11 retrieves the corresponding area-specific information from area [01] of the data memory 12, recognizes the start address of the correspondingly stored decoding algorithm program, and performs the corresponding decoding algorithm. The algorithm program is executed to decode the data previously held in the RAM, and the decoded data is output to the card reader/writer 2 as response data. Then, the control element 11 returns to the command data holding state again.

According to the IC card described above, it is possible to assign a pair of encryption/decryption algorithms for data writing and data reading to each area of the data memory, so that a single encryption/decryption algorithm can be assigned to each area of the data memory. Compared to those that perform encryption and decryption processing using a pair of algorithms,
The encryption/decryption algorithm pair is difficult to decipher, making it possible to protect data even if the data is read out illegally, making it possible to build a system with high security.

In the above embodiment, the IC card 1 is used as an example of a portable electronic device, but the present invention is not limited to a card-shaped device, and may be a block-shaped or pencil-shaped device, for example. Furthermore, the hardware configuration of the portable electronic device can be modified in various ways without departing from the spirit of the invention.

[Effects of the Invention] As detailed above, according to the present invention, the encryption/decryption algorithm pair is difficult to decipher, and data can be protected even when data is read out illegally, resulting in a highly secure system. It can provide a portable electronic space where things can be built.

[Brief explanation of the drawing]

The figures are for explaining one embodiment of the present invention. Figure 1 shows the configuration of a program memory, and Figure 2 shows the correspondence between area-specific information and encryption/decryption algorithms versus the start address of the program. FIG. 3 is a diagram showing the configuration of the data memory, FIG. 4 is a flowchart explaining the data write operation, FIG. 5 is a diagram showing an example of the format of write command data, and FIG. 6 is a diagram showing the data read operation. FIG. 7 is a flowchart explaining the operation, FIG. 7 is a diagram showing an example of the format of read command data, FIG. 8 is a block diagram showing the structure of the IC card, and the ninth factor is a block diagram showing the structure of the card handling device. 1...IC card (portable electronic device), 2.
...Card reader/writer, 11...--1
1m element (t! control section), 12... data memory (data memory section), 13... program memory (program memory section). Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 Figure 2 Figure 5 Figure 7 Figure 3 Figure 4 Figure 6

Claims (3)

[Claims] (1) In a portable electronic device that has a data memory section and a control section for reading and writing data to the data memory section, and selectively performs input/output from the outside; - A decryption algorithm pair is registered, and the data memory section is divided into multiple areas, and an encryption algorithm is used to encrypt and decrypt data when writing and reading data in the area from the outside.・
A portable electronic device characterized in that a pair of decoding algorithms is determined by each area. (2) A patent claim characterized in that specific information corresponding to all the areas is stored in at least one of the areas, and the encryption/decryption algorithm pair is determined based on this specific information. The portable electronic device according to item 1. (3) The plurality of encryption/decryption algorithm pairs are registered in a program memory section that stores a control program for control by the control section. portable electronic devices.