JPH036792A - Method for ciphering/deciphering ic memory card - Google Patents

Abstract

PURPOSE:To add a security function to an IC memory card by recombining corresponding relation between connection parts and signal lines to connect them in an IC memory card reader/writer. CONSTITUTION:In the IC memory card reader/writer, the corresponding relation between the connection parts and the signal lines in recombined to connect them. Even when meaning data are written, the data are written in the card in a random order and the data have different means or no meaning, i.e. the data are ciphered. Since the cipher is formed based upon a fixed rule uniformly determined by the recombination, the original data can be read out by the same recombination without generating any trouble and restored. Consequently, the contents of data can be made secret without generating any trouble in operation.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention provides data and programming on an IC memory card.
This is an attempt to add a security function to an IC memory card.

[Conventional technology]

2. Description of the Related Art IC memory cards have come to be widely used as external storage media for information processing devices in place of floppy disks.

To avoid confusion in data processing, the interface section of an IC memory card is now connected in accordance with the signal line attributes of the data processing section used in the main unit to which the IC memory card is connected. It is common that In other words, address line No. 3 is connected to address line No. 3 of the IC memory card, and data line No. 5 is connected to address line No. 3 of the IC memory card.
No. 5 is connected to data line No. 5 of the IC memory card.

However, as described above, if the signal line attributes match, the contents can be easily read, so there is a problem that important data cannot be kept secret and expensive programs can be easily copied.

[Problem to be solved by the invention]

The present invention aims to solve these problems of conventional IC memory cards in a simple manner and add security functions to IC memory cards.

[Means to solve the problem]

The present invention includes a plurality of connection parts for electrically connecting with terminal parts of an IC memory card, and a control part that controls data exchange between the IC memory card and a data processing part via a plurality of signal lines. This is a method for encrypting and decoding an IC memory card, which is characterized in that in an IC memory card reader/writer consisting of the following, the correspondence between a connection part and a signal line is rearranged to make them tangential.

Specifically, data lines and address lines are treated separately; if the data lines are 8 bits, they are treated as one set, and if the data lines are 16 bits, 16 bits are treated as one set, depending on the operating form of the data processing section. Alternatively, the address lines are rearranged by making two sets of the upper 8 bits and the lower 8 bits, and the address lines are rearranged by making the whole set into one set. Of course, each of the above-mentioned sisters may be further subdivided, for example, the data lines may be divided into groups of 4 points each.

Although there are no particular limitations on the means of rearranging, it is possible to rearrange the correspondence between the connection parts and signal lines in advance during the manufacturing stage of the reader/writer, and connect the connection bands and jumper wires on the printed wiring board by soldering, etc. Although they may be fixed by any method, using a connecting means such as an IC socket and a jumper wire allows the user to rearrange and use them as desired, which is more preferable from the viewpoint of security.

By doing this, even if you write meaningful data, it will be written in a seemingly random order inside the card.
Moreover, the data has a meaning different from the original, or has no meaning at all, that is, it has become a code. Of course, this follows a certain order that is uniquely determined by recombination, so by the same recombination, it can be read without any problem and the original data can be restored.

〔Example〕

As a simple example, a case will be described in which data is written to a memory element having a 4-bit data line and a 4-bit address line. Table 1 shows the data on the signal line and the same data in the memory when writing in the conventional normal state. When the data lines and address lines are rearranged,
The data on the signal line is shown, and Table 3 is the second table in memory at that time.The data on the signal line after recombination is completely different data, in other words, it is a code, and it is completely different from where it should be. It can be seen that it is stored in

〔Effect of the invention〕

As described above, when the present invention is applied and the data written via the reader/writer is read out in a normal connection state, the data is read out in a completely different form in a seemingly random order. As a result, it is almost impossible to know the original data without knowing how to rearrange the signal lines. If you rearrange this in the same way and read it out, you can read out the original data without any problems.
By passing through a reader/writer to which the present invention is applied,
Even in memory cards, for which it was originally difficult to keep data confidential, it is now possible to keep the contents secret without interfering with operation.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of signal line rearrangement in the present invention. Data processing section side card connection section side address line A, s A+ A1 A-? ? ? ? Address line data line Ds Dt Dr D. 11 [T data line

Claims (1)

[Claims] (1) A plurality of connection parts for electrically connecting to the terminal part of the IC memory card, and an I
An IC memory card reader/writer comprising a control section that controls data exchange between a C memory card and a data processing section, which is characterized in that the connection is made by rearranging the correspondence between the connection section and the signal line. Encryption/decryption method.