JPH01174139A - Encipherment method and its device - Google Patents

Abstract

PURPOSE:To sufficiently secure the secrecy of a data with a simple method by setting an encipherment key and the number of times of use of the encipherment key based on a pattern of an initial data. CONSTITUTION:When an initial data in inputted, an initial data deciding section 4 decides it as the initial data and an encipherment key setting section 5 sets the encipherment key based on the pattern of the initial data and the number of times of the use is set by the number of times use setting section 3 of the encipherment key. An encipherment section 10 based on the set encipherment key applies sequential encipherment to the initial data and outputs the result. Simultaneously, the counted value of the number of times setting section 3 is decremented by one. The input data encipherment processing by the encipherment key is applied till the counted value of the section 3 reaches zero and when the counted value reaches 0, the next input data is regarded again as the initial data and the encipherment key is set by an encipherment key setting section 6 to encipher the input data.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to an encryption method for encrypting data or decoding encrypted data, for example in the field of data communication using wide area networks. and its equipment.

[Conventional technology]

Conventionally, in satellite communication systems, loop network systems, branch line systems, etc., a third party intervenes in the network, and there is a risk that data may be stolen or manipulated by a third party. When data communication becomes widespread.

The danger and instability cannot be ignored, and there is a risk that the spread of data communications will be hindered. Therefore, encryption is required to maintain secret communication between users.

Well-known encryption methods include the substitution method, which uses a password or key to perform an operation that is inverse to the input data to perform the encryption process, and the conversion method, which performs the encryption process by changing the order within a block of data. There are fonts, etc. However, it is believed that it is possible to break the encryption using just one of these methods, and to prevent this, it is usually not possible to do so (using complex combinations of several methods makes it almost impossible to guess the key or password).

[Problem that the invention seeks to solve]

Conventional encryption processing uses a complex combination of several methods, as described above, to make it sufficiently resistant to code breaking.

There was a problem that the entire system became complicated.

This invention was made to solve the above-mentioned problems, and is sufficiently effective for breaking codes.

Moreover, the object is to obtain a simple encryption method and device.

[Means for solving problems]

The encryption method and device according to the present invention, when encrypting data in units of predetermined bits, use first manual data as initial data, and based on the pattern of this initial data, create an encryption key and the number of uses of this encryption key. The encryption key is used to encrypt subsequent data for the number of times it is used, and when this encryption is completed, the next first input data is set as the initial data, and the above encryption can be continued thereafter. be.

[For production]

In the encryption method and device of the present invention, the encryption key and the number of uses of this encryption key are set based on the pattern of the initial data.

Data encrypted using a plurality of encryption keys are consecutively connected in irregular numbers for each encryption key.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, reference numeral 111 has a function that also serves as an encryption/decryption device, and is simply referred to as an encryption device.

(2) is the input data to be encrypted that is input to this encryption device II+, and (3) is the encryption key in which the pattern of the initial data is set in the counter as the number of times the encryption key is used, and the input data (2;) is counted for the number of uses. Key usage count setting section,
(41 is an initial data determination unit that reads the counter of this encryption key usage count setting unit + 31 and determines the next input data as the initial data when it is “0”; (5) selects and specifies the encryption method. Encryption method specification section.

(6) is an encryption key setting section that sets which encryption key is used to actually encrypt the data to be encrypted, and (7) is an encryption key setting section that specifies whether to perform encryption or decryption for this encryption key setting section (6). (8) an encryption/decryption specification section that specifies whether encryption is to be performed;
is a gate section for disabling the output of the encryption key setting section (6), and when it is the first data, the first data judgment section (4)
The output signal of the encryption key setting unit (6) is cut and invalidated by the output signal from the encryption key setting unit (6), and the first data is encrypted using a circular encryption method different from the method used by the encryption key setting unit (6). Encryption method 1 is used for the first data, and method 2 is used for the second data.

Repeatedly from the nth time onwards, the first encryption method 1 is used.
The method of returning to the original ring shape is set in the ring-shaped encryption setting section (91). fi (1 is the encryption key setting section (61
This is an encryption unit that actually applies the encryption method set in 2 to input data (2). aυ is an operation command unit for instructing whether or not to operate this encryption unit fiG, and has the role of prohibiting the operation of the encryption unit aa for input data (2) that does not require encryption. take charge α2 is the input data (
2) is used as output data as is.
fill is output data.

The specific operation of the encryption device 11) will be described below.

First, Figure 2 shows the relationship between input data (2) and output data (1) of the encryption device (1). In the figure, A1.A2.A3. . . . indicates the output data in which the first data is encrypted, and B1.B2゜B3
．． . . . indicates the number of pieces of data that are consecutively encrypted using the encryption key set by each initial data.

Next, FIG. 3 shows the operational flow of the encryption device +11. The specific operation of the encryption device (1) will be explained based on FIG. Since the counter of the encryption key usage number setting section (3) is "0", the input data is determined to be initial data by the initial data determination section (4). Therefore, in step α9, the initial data enters the encryption key setting unit (5) to set the encryption key, and at the same time, the initial data enters the counter of the encryption key use number setting unit (3) to set the number of uses. Next, in step αe, the encryption key usage count setting section (
3) Check the counter, and if it is "0", that is, if the initial data is "0", move to the step gradient and read the next input data. If the initial data is not “0”, step α
Moving to step D, the first data is subjected to circular encryption and outputted, and at the same time, "1" is subtracted from the counter of the encryption key usage number setting section (3). Next, in step α♂, the counter of the encryption key use count setting section (3) is checked, and if it is "0", the process moves to step 4, and then in step G, it is checked whether all data has been completed and there is no next input data. If the next input data is available, the process returns to step α9. If the counter of the cryptographic key usage number setting unit (3) is not "0" in step αorange, this indicates that the number of usages has not been completed, so the next input data is read in the next step a9.

At this point, if there is no next input data, all data is finished, and the process goes through step (3) and ends. If there is next input data, step C! At υ, the input data is encrypted with the encryption key determined in step α9 and output, and at the same time, "
1” is subtracted. Next, return to step a8 and check the counter of the encryption key use count setting section (3). If it is "O", it means that the number of uses has ended, so read the next input data and set it as the initial data. However, if the counter is not "0", the number of uses has not ended, so step c! Perform processing in D. Thereafter, encryption is continued using the same encryption key in step QD until the counter in step αa reaches "0", and when the counter in step aS reaches "0", the number of uses ends and the next input data is input for the first time. It will be treated as data. In addition,
It is necessary to externally set the states of the encryption/decryption specifying section (6) and the operation command section QG before starting the above operation.

Encryption is performed as described above.

An example of how the encryption key is determined based on the initial data is shown below.

There are various possible circular encryption methods for initial data, but in this usage example, the first initial data is rotated by 1 bit to the right, and the next initial data is rotated by 1 bit to the left. A repeating encryption method was used. Here, a 1-bit rotational shift to the right means shifting 1 bit to the right and moving the amount shifted to the right end to the empty bit on the left end.For example, 3-bit data '
Shifting 011" one bit rotation to the right gives 1101", and shifting 1011" one bit rotation to the left gives 11.
The number of bits of the data to be handled is 8 bits, and the configuration diagram of the encryption key based on the initial data is shown in FIG. 4, and the constant contents of each part of the bits forming the encryption key are shown in Table 1.

These are the mode part, modification part, and prohibition part. The mode part is M.

The encrypted contents shown in Table 1 were defined for each of four types of combinations of 2 bits and 1.0 of MO, each consisting of 2 bits for a total of 4 bits. The modification part consists of 3 bits and serves to modify the definition contents of the mode part by using 0 to 7, which is a 3-digit binary number converted into a decimal number, as n. The prohibition part consists of 1 bit, and Ml of the mode part is determined by combining various conditions shown in Table 1.

M,) is prohibited.

Table 1 Encryption key part Definition Contents 00 1's complement M,, Mo 01 2 (mode part) +
01 Bit rotation shift to the right 11 Invert the 1.0 of the bit of bit number n n Specify the shift number in the case of 10 above and the pit (modification part) in the case of 11.

F=o M, %M, , M, (7)
After “・0 encryption execution” = MOMo O:) Mi// (Prohibited part) The bit of bit number ■ is M
, cr+mi//, -61 Since this embodiment is constructed as described above.

Despite the simple encryption method shown in the usage example in Figure 4, the maximum number in 8 bits is '11111111.
The encryption key changes every irregular number of items up to 255 converted into decimal numbers, and the encryption key is set by the input data itself, so the encryption key changes irregularly, and the output data makes guessing the encryption key almost impossible.

Note that if decryption is specified in the encryption/decryption specification section (7).

The input data is subjected to a process opposite to that of encryption, and the encrypted data is decrypted and output as output data for decoding.

〔Effect of the invention〕

This invention is configured as described above.

Both the encryption key and the number of times the encryption key is used are changed irregularly depending on the initial data, making it almost impossible to guess the encryption key from the output data, making it possible to obtain a simple encryption method and device. be.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an encryption device according to an embodiment of the present invention, FIG. 2 is a conceptual diagram showing the relationship between input data and output data, FIG. 3 is a flowchart showing processing of the encryption device, and FIG. The figure is an encryption key configuration diagram when the number of bits of data handled is 8 bits as an example of use. In the figure, (l) is an encryption device, and 12) is input data. (3) is an encryption key use count setting section, (4) is an initial data determination section, (5) is an encryption/decryption specification section, and (6) is an encryption key setting section. (7) is the encryption/decryption designation section, (8) is the gate section, (9) is the circular encryption setting section, αG is the encryption section, αυ is the operation command section, C13 is the classification section, (13 is the output data Note that the same reference numerals in Figure 9 indicate the same or equivalent parts.

Claims (2)

[Claims] (1) When encrypting data in units of predetermined bits,
The first input data is the initial data, an encryption key and the number of uses of this encryption key are set based on the pattern of this initial data, subsequent data is encrypted with the encryption key and the number of uses, and this encryption is completed. An encryption method characterized in that the next first input data is set as the initial data when the data is input, and the encryption is automatically changed according to the pattern of the initial data each time. (2) When encrypting data in units of predetermined bits,
An encryption key setting section that sets an encryption key based on the pattern of the first input data; an encryption key usage count setting section that sets the number of uses of the encryption key based on the pattern of the initial data; A cipher characterized by comprising an encryption unit that encrypts the data, an initial data determination unit that determines the first input data as the initial data, and determines the first input data after the number of times the encryption key is used as the initial data. conversion device.