JPS6189743A - Ciphering system - Google Patents

Abstract

PURPOSE:To generate a cipher difficult for decoding by applying change in character position designated by character location designation information to assemble a ciphered text, selecting plural test ciphering elements as informa tion to be added and transmitting the result. CONSTITUTION:One character designated by a register 5 is stored in a register 6 for ciphered characters among texts stored in a register 1. Operating informa tion of character ciphered elements designated by the register 5 is stored in an operation number register 7 among one test ciphering element designated by the register 4, an operator designating the kine of the operation to be conducted is stored in an operator register 8, and character location change designation information designating the character location in a register 3 of the ciphered charater is stored in a character location designating register 9. An operation controller 11 controls an arithmetic unit 10 depending on the content of the register 8. One character ciphered by the arithmetic unit 10 is stored sequentially in an output text register 3 via a register 12.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an encryption method for information in data communication between a terminal device and a central processing unit.

(Prior art) Online systems in which terminal devices and central processing units are connected via communication lines are used in financial institutions such as banks, seat reservations in national railways and airlines, air traffic control, defense organizations, and production management in factories. It has come to be used in many different ways.

Recently, as portable portable terminal devices have begun to be adopted as components of online systems, online systems have started to appear that use public communication (regular subscriber telephone) lines, rather than limited to conventional specific communication lines. Ta.

On the other hand, as technology and equipment for monitoring these communication lines have developed, social problems have arisen due to, for example, wiretapping of communication lines in financial institution systems. For this reason, it has been considered to encrypt the information sent to the communication line and decode it to its original form on the receiving side.

(Problems to be Solved by the Invention) However, in conventional systems of this type, a method has been adopted in which a modem with a blank/pull function or a 2-encryption device is externally connected between the terminal device and the communication line. Because I was
There is a drawback in that the terminal device itself and the modem or external device are vulnerable to eavesdropping between the encryption device.

Also, when encrypting, 1, for example, the number "0" i
A simple conversion such as converting to the alphabet "A" has the disadvantage that it is easy to decipher by eavesdropping.

Therefore, an object of the present invention is to provide a unit of information that is transmitted and received at a time (
The purpose of this method is to create a code that is difficult to decipher by performing a different encryption operation for each character position of a text (hereinafter referred to as text).

Another object of the present invention is to realize an encryption method that is difficult to eavesdrop on by implementing an encryption operation by internal operation of a terminal device.

(Means for solving the problem) According to the present invention, corresponding to each character position in the text,
Set a text encryption element that has at least the number of character encryption elements that are a set of calculation information for encryption, an operator, and character position change specification information, and the number corresponds to the maximum length of the text to be transmitted, and this A key table having a plurality of text encryption elements is provided, and for each text to be transmitted, one of the plurality of text encryption elements in the key table is selected and the text to be transmitted is scanned character by character; The text to be transmitted is encrypted character by character according to the corresponding character encryption element among the text encryption elements selected corresponding to each character position, and the character position within the text is changed according to the character position change specification information. An encryption method is obtained in which the modified encrypted text is assembled, information used to select the plurality of text encryption elements is added, and the encrypted text is transmitted.

(Example) Next, the present invention will be described in detail with reference to drawings showing examples of the present invention.

In FIG. 1, an input text register IFi stores the text to be encrypted. The storage device i stores a key table including a plurality of □ (this embodiment ÷ 4) enemy text encryption elements 21, 22, 23, and 24 for encryption. The output text register 3 stores nine texts that have undergone encryption processing.

The instruction register 4 has a plurality of text encryption elements 21 to 2.
Store information for selecting one of the four options. The character position designation register 5 designates a character encryption element within the text encryption element corresponding to each character position of the month of the month and the character position of the text to be encrypted. The encrypted character register 6 contains the text stored in register l,
One character specified in register 5 is stored. The arithmetic register register stores the operation information for the character encryption element specified in register 5 among the N1 text encryption elements specified in register 4, and the operation -5 = operator register 8 is stored. stores an operator that designates the type of operation to be performed, and further stores character position change designation information that designates the character position of the encrypted character in the register 3 in the character position designation register 9. Arithmetic controller 11
controls the arithmetic unit IO according to the contents of the register 8. One character encoded by the arithmetic unit 10 is stored in the register 12t.
- are sequentially stored in the output text register 3 through the output text register 3.

Referring to FIG. 2, one character encryption element in the text encryption element has calculation information (operation number) 3 for encryption.
1. Operator for encryption 32. and character position change designation information 33.

Referring to FIG. 3, 4
The character encryption elements a, b, c, . . . , nl shown in FIG. 2 each have a plurality of text encryption elements. The number of character encryption elements is provided equal to the maximum length of characters constituting the text to be encrypted stored in register l.

Next, the encryption process will be explained.

First, the text to be transmitted is stored in register l, register 3 is cleared, and character position specification register 5 is cleared.
is reset to zero. Next, information for selecting one of the plurality of text encryption elements 21, 22, 23, and 24 is set in the register 4. This information may be the output of a counter that increases or decreases each time one text is transmitted, or the output of a random number generator. It is assumed here that the information selected by the text encryption element 21 has been set.

Next, the content tl of the character position designation register 5 is increased.

As a result, one specified character in register 1 is taken out into register 6. Similarly, register 7 contains the calculation information 31 that constitutes the specified character encryption element in the text encryption element 21, and register 8 contains the operator 32 to be applied to the operation number. is character position change specification information 3 that specifies the storage position of the calculation result in register 3
3 are taken out respectively. Arithmetic unit 10 performs the arithmetic operation specified by register 8 on the contents of registers 6 and 7 under the control of arithmetic controller 11 and stores the result in register 12 . One character of the encrypted text in register 12 is stored in register 3 at the character position specified by register 9.

When one character in register l is thus encrypted and stored in register 3, the contents of register 5 are incremented by 1, and the process returns to the operation of fetching one character from register l into register 6. Once all characters of the text to be encrypted in register 1 have been encrypted, the encrypted text includes the contents of register 4 that were used to select one of the multiple text encryption elements. is added, and a transmission control code indicating the start of the text, the station number of the destination or source, the end of the text, etc. is added, and the message is sent to the destination.

It is clear that the text encrypted in this manner can be decrypted on the receiving side by restoring the original character position to the original character position using the same key table as on the sending side and then performing an inverse operation.

Next, a second embodiment of the present invention will be described.

In FIG. 4, blocks that are the same as in the first embodiment are given the same reference numerals. The difference from the first embodiment is that the text encryption element 21 stored in the instruction register 4.
The instruction information of 22.23.24 is taken from the voice table register 13 ff1f. For this reason, the pointer table 13 is further provided with a register 14 for selecting one of the plurality of pieces of instruction information. The other constituent elements are the same as those in the first embodiment, so their explanation will be omitted.

Next, the encryption process in the second embodiment will be explained.

The process is the same as the first embodiment until the text to be transmitted is first stored in register 1, register 3 is cleared, and the character position specification register is reset to zero. Next, in order to select 1M of the plurality of text encryption elements stored in the storage device 2, one of the plurality of instruction information stored in the pointer table 13 is selected.

Therefore, the output of a counter or the output of a random number generator is set in the register 14, which increases or decreases each time one text is transmitted. One piece of instruction information in the pointer table 13 selected in this way is entered into the instruction register 4, and one of the plurality of text encryption elements is selected. The subsequent operations are the same as in the first embodiment.

When all the characters of the text to be encrypted in the register 1 have been encrypted, the encrypted text contains information used to select one of the plurality of instruction information in the voice/vertical table 13. The contents of the registered register 14 are added, and the start of the text, the destination or source station number,
A transmission control code indicating the end of the text is added and sent to the destination.

It is clear that the text encrypted in this manner can be decrypted on the receiving side by performing an inverse operation using the same pointer table and key table as on the sending side.

In the second embodiment of the present invention, one of a plurality of text encryption elements is selected by the instruction information in the pointer table, so the contents of the ball 〇- ink table are changed. It is possible to realize an encrypted information transmission system in an online system that is more difficult to decipher.

In the encryption operation, it is necessary to select the operation information and the operator t so that the characters in the text are not converted into control codes for transmission control by being encrypted. . Furthermore, when decoding is performed on the receiving side, it is necessary to select calculation information and operators that will not cause the original text information to be lost. In addition, in the above description, the example in which the number of text encryption elements is four has been described, but the present invention is not limited to this. - (Effects of the Invention) As explained above, the present invention uses a key table including a plurality of text encryption elements to select a different text encryption element for each text.

By encrypting the text, it is possible to prevent the data communication 5 information in the online system from being intercepted.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first embodiment of the present invention, and FIG.
FIG. 3 is a diagram showing the configuration of a character encryption element, FIG. 3 is a diagram showing the configuration of a text encryption element, and FIG. 4 is a block diagram showing a second embodiment of the present invention. 1...Text register, 2...-Storage device, 3...Output text register, 4...
...Text encryption element specification register, 5...
・Character position specification register, 6.12...Register for one character, 7......Arithmetic information register, 8.
...... Operator register, 9... Character position change specification information register, 10... Arithmetic unit, ll
...... Arithmetic controller b13... Pointer table register, 14... Instruction information specification register. 1 Kaiho 3 Kai 4'I ¥] Or: 7

Claims (1)

[Claims] Corresponding to each character position in the text, a character encryption element consisting of a set of arithmetic information for encryption, an operator, and character position change designation information is provided that corresponds to at least the maximum length of the text to be transmitted. a key table having a plurality of text encryption elements, and selecting one of the plurality of text encryption elements in the key table when transmitting text; The text to be transmitted is encrypted character by character by reading the corresponding character encryption element of the selected text encryption element corresponding to each character position of the text to be transmitted, and the character position is specified. An encryption method characterized in that an encrypted text is assembled by changing the character position specified by the information, and information on selecting the plurality of text encryption elements is added and transmitted.