JPH02129784A - Ic card - Google Patents

Abstract

PURPOSE:To improve the confidentiality of data at the time of transferring data between an IC card and an external part by transforming the bit arrangement of the data to the arbitrary arrangement in a data transforming means and transferring the data. CONSTITUTION:When the data are outputted, the data on a data bus 1 are once latched to a data buffer 2 and these latched data are transformed to the bit arrangement which is determined in a bit arrangement rearranging circuit 10. Next, these transformed data are sent to a parallel/serial converting circuit 3 and parallel data are converted to serial data. Then, the data are outputted from an external terminal 3a. In such a way, the bit arrangement of the data is rearranged and the data are transferred. Thus, there is no danger that the data are read by the third person. Namely, the confidentiality of the data can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an IC card that transfers data to and from the outside.

[Conventional technology]

FIG. 4 is a block diagram showing an input/output circuit in a conventional IC card. In the figure, 1 is a data bus, 2 is a data buffer, and 3 is a parallel/serial conversion circuit. Note that 3a is an external terminal connected to the parallel/serial conversion circuit 3.

Next, conventional data input and data output operations of an IC card will be explained. First, in the case of data input, serial data input from the external terminal 3a is sequentially stored in the parallel/serial conversion circuit 3. When a certain amount of data is input, it is converted into parallel data by a control signal from a CPU (not shown).
Sent to data buffer 2. Next, data buffer 2
The data once stored in is sent to the data bus 1 by a control signal from the CPU. Data input is thus performed by repeating the above operations.

Next, when outputting data, the data on the data bus 1 is latched into the data buffer 2 by a control signal from the CPU. The latched data is then sent to the parallel/serial conversion circuit 3, which converts the parallel data into serial data, and outputs the data from the external terminal 3a. In this way, data is output by repeating the above operations.

[Problem to be solved by the invention]

Conventional IC cards are configured as described above, so
The method for data transfer between the IC card and the outside is either a method that starts from the most significant bit (MSB first) or a method that starts from the least significant bit (LSB first).

For this reason, with IC cards that may handle confidential information,
There was a possibility that the data could be read by a third party during data transfer.

The present invention was made in order to solve the above-mentioned drawbacks, and an object of the present invention is to obtain an IC card that improves the confidentiality of data during data transfer between the IC card and the outside.

[Means to solve the problem]

The IC card according to the present invention is equipped with a data conversion means that changes the bit arrangement of data to an arbitrary arrangement and transfers the data when data is transferred to the outside.

[For production]

The data conversion means converts the bit array of the data into an arbitrary array and transfers the data.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a functional block diagram of an IC card showing one embodiment of the present invention. In the figure, 4 is the CPU, 5 is the ROM, and 6 is the CPU.
7 is a RAM, 7 is an EEPROM, 8 is a bus, and 9 is an input/output circuit. The same parts as in FIG. 4 are given the same reference numerals. 1
0 is a focus arrangement recombination circuit.

FIG. 2 is a circuit diagram of the input/output circuit 9 in FIG. 1.

In the figure, the same parts as in FIG. 4 are given the same reference numerals.

10 is a bit arrangement recombination circuit.

FIG. 3 is a circuit diagram showing a specific configuration of the bit arrangement recombination circuit 10 shown in FIG. 1. In the figure, 11 is a launch circuit, and 12 is a gate.

Next, in the above configuration, the operation of the IC card during data input and data output will be described. First, in the case of data input, serial data input from the external terminal 13a is input to the parallel/serial conversion circuit 3. Next, the parallel/serial conversion circuit 3
According to the control signal from 4, the serial data is converted into parallel data, and this data is sent to the focus arrangement recombination circuit 10. The bit arrangement recombination circuit 10 launches the data input to the latch circuit 14 shown in FIG.

Thereafter, according to the bit arrangement predetermined between the IC card and the external device, the upper and lower gates of the gates 12 are turned on one bit at a time to rearrange the bits into a regular bit arrangement.

For example, when converting 1st bit data into 3rd bit data, the gate 12 connected to the 1st bit latch circuit 11 is turned on, and all other gates are turned off.

Next, the data is latched into the third bit launch circuit 11 on the opposite side. With this operation, the 1st bit data becomes 3
Converted to bit data. In this way, by performing the above operation one bit at a time, after converting all eight bits, the rearranged data is sent to the data buffer 2. Then, data is transferred to data bus 1 from data output time 2 .

Next, when outputting data, the data on the data bus 1 is launched to the data bus sofa 2 once. The latched data is then converted into a predetermined beat/beat arrangement by the bit arrangement recombination circuit 10. Next, this converted data is sent to the parallel/serial conversion circuit 3, which converts the parallel data into serial data, and outputs the data from the external terminal 3a.

In this way, the IC card in this embodiment uses the bit arrangement recombination circuit to recombine the bit arrangement of data and transfer data, so there is no worry that the data will be read by a third party, and the confidentiality of the data is increased. be able to.

In the above embodiment, the case where the bit array recombination circuit 10 is provided between the parallel/serial conversion circuit 3 and the data buffer 2 has been described. Good too. Furthermore, the latch circuit 1 in the bit arrangement recombination circuit 10
1 may be shared with data buffer 2.

〔Effect of the invention〕

As described above, the present invention is advantageous in that the data conversion means recombines the bit arrangement of the data and transfers the data, so there is no need to worry about the data being read by a third party, and the confidentiality of the data can be increased. have an effect.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an input/output circuit of an IC card showing an embodiment of the present invention, FIG. 2 is a functional block diagram of an IC card, third is a circuit diagram of a bit arrangement recombination circuit 10, and FIG. 4 is a conventional circuit. FIG. 2 is a block diagram of an input/output circuit in the IC card of FIG. 1...Data bus, 2...Data buffer, 3...
Parallel/serial conversion circuit, 10... bit arrangement recombination circuit.

Claims (1)

[Claims] 1. An IC card capable of data transfer, characterized in that the IC card is equipped with a data conversion means for recombining the bit arrangement of data into an arbitrary arrangement and transferring the data when data is transferred to an external device.