JP2661086B2 - Encryption method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to, for example, in the field of data communication using a wide area network, encryption for encrypting data or decrypting encrypted data. It is about the method. [Prior art] Conventionally, in a satellite communication system, a loop network system, a branch circuit system, etc., there is a danger that a third party intervenes in the network and that the third party may steal or process data. Also, as in recent years, especially when data communication is spread over a wide area, its danger and instability cannot be ignored, and it may hinder the spread of data communication. Therefore, encryption is required to keep confidential communication between users. As a well-known encryption method, there are a substitution method in which an operation that has an inverse operation with respect to input data is performed by using a password or a key to perform an encryption process, and a conversion method in which an encryption process is performed by changing the order in a block of data. There are writing methods. However, only one of these methods is capable of deciphering, and in order to prevent this, it is usually impossible to guess a key or a password by combining several methods in a complicated manner. [Problems to be Solved by the Invention] In the conventional encryption processing, by combining several methods in a complicated manner as described above, the encryption processing has an effect enough to withstand encryption breakage. There was a problem that it became complicated. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a simple encryption method that has a sufficient effect on cipher breaking. [Means for Solving the Problems] In the encryption method according to the present invention, the number of times of use of an encryption key is set based on the pattern of the first input data in a predetermined bit unit when encrypting data. Encrypts the subsequent data up to the number of times, and when this encryption is completed, sets the number of times the encryption key is used based on the pattern of the next first input data, and continues encryption of the subsequent data in the same manner as above This is done by doing. [Operation] In the encryption method according to the present invention, the number of times the encryption key is used is set based on the pattern of the initial data.
The first data is generated every irregular number of times. Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In FIG. 1, (1) has a function also serving as an encryption / decryption measure, and is simply called an encryption device. (2) is input data to be encrypted to be input to the encryption device (1),
(3) sets the pattern of the initial data as the number of uses of the encryption key in the counter, and inputs data for the number of uses (2)
(4) reads the counter of the encryption key usage count setting unit (3), and when it is "0", the first data determination unit determines the next input data as the first data. 5) is an encryption key setting unit for setting which encryption key is actually used to encrypt the data to be encrypted. In this example, the encryption key setting unit encrypts data subsequent to the first initial data of the ring encryption method. In the second encryption method, the second encryption method is used, and after the n-th encryption method, the method returns to the first encryption method 1 and returns to the original encryption method. (6) is the encryption key setting unit (5)
An encryption / decryption designation unit for designating whether encryption or decryption is to be performed on the data, and (7) a gate unit for invalidating the output of the encryption key setting unit (5). At this time, the output signal of the encryption key setting unit (5) is cut off by the output signal from the first data determination unit (4) to invalidate it, and the ring encryption method is set for the first data by the ring encryption setting unit of (9). I do. (9) is an encryption unit for actually applying the encryption method set by the encryption key setting unit (5) to the input data (2). (10) is an operation command section for instructing whether or not to operate the encryption section (9), and operates the encryption section (9) for input data (2) for which encryption is unnecessary. Play a role in prohibiting (11) is a classification unit for determining whether data encrypted by the encryption unit (9) is output data or input data (2) is output data as it is, and (12) is output data. . The specific operation of the encryption device (1) will be described below. First, FIG. 2 shows the relationship between the input data (2) and the output data (12) of the encryption device (1). In the figure, A ₁ , A ₂ , A ₃ ... Indicate output data in which the initial data is encrypted, and B ₁ , B ₂ , B ₃ ,. The number of cases is shown. Next, FIG. 3 shows an operation flow of the encryption device (1). The specific operation of the encryption device (1) will be described with reference to FIG. 3. The counter of the encryption key usage count setting unit (3) is set to "0" simultaneously with the encryption start command of the operation command unit (10). The first input data is determined to be the first data by the first data determination unit (4) for which the counter of the use frequency setting unit (3) is "0" using the encryption key.
Then, in step (15), the initial data enters the encryption key setting section (5) and the encryption key is changed. At the same time, the initial data enters the counter of the encryption key usage count setting section (3) to set the usage count. Next, in step (16), the counter of the encryption key usage count setting section (3) is checked. If the counter is "0", that is, if the first data is "0", step (22) is performed.
Move to and read the next input data. If the initial data is not "0", the process proceeds to step (17), where the initial data is subjected to circular encryption and output, and at the same time, "1" is subtracted from the counter of the encryption key usage count setting unit (3). Next, in step (18), the counter of the encryption key usage count setting unit (3) is checked. If the counter is "0", the process proceeds to step (22). Then, in step (23), it is checked whether or not all data is completed. If there is no input data, the process ends, and if there is another input data, the process returns to step (15). If the counter of the encryption key usage count setting unit (3) is not "0" in step (18), it indicates that the usage count has not ended, so the next input data is read in the next step (19). Here, if the next input data is absent, all the data ends and the process ends at step (20). If there is the next input data, step (1) is executed for the input data in step (21).
At the same time as encrypting and outputting with the encryption key determined in 5), "1" is subtracted from the counter of the encryption key usage count setting unit (3). Next, returning to step (18), the counter of the encryption key usage count setting section (3) is checked. If the counter is "0", it indicates that the usage count has been completed, so the next input data is read and read. Although it is handled as the first data, if the counter is not "0", the processing in step (21) is performed because the number of uses has not been completed. Thereafter, the encryption using the same symbol key in step (21) is continued until the counter in step (18) becomes “0”, and the number of times of use ends when the counter in step (18) becomes “0”. Then, the next input data is handled as the first data. The states of the encryption / decryption designation unit (6) and the operation command unit (10) need to be set externally before the above operation is started. Since this embodiment is configured as described above, the number of times each encryption key is used is set irregularly based on the pattern of the initial data, despite the simple encryption method. Guessing the encryption key from the output data makes it almost impossible. When the decryption is designated in the decryption designating section (6), the input data is subjected to the reverse process of the encryption, and the encrypted data is decrypted and output as output data for decryption. [Effects of the Invention] According to the present invention, in encrypting data, first input data in a predetermined bit unit is used as initial data, and an encryption method (encryption key) based on a pattern of the initial data, Since the range covered by the encryption method is set, there is an effect that the apparatus can be simplified and the apparatus cost can be reduced as compared with the conventional method of separately creating / setting these. Further, according to the present invention, the encryption method (encryption key) is fixed within one data unit by encrypting the subsequent data for each predetermined bit unit using the encryption key up to the set number of times of use. There is an effect that even within one data unit, it can be arbitrarily changed within a range depending on the initial data. Further, according to the present invention, when the encryption is completed, the next first input data is first data, and the number of times the encryption key is used is automatically changed according to the pattern of the first data each time. Since the encryption method (encryption key) and the range of influence change irregularly within the unit, there is an effect that the encryption strength of the transmitted / received data can be increased. Further, according to the present invention, two types (plural) types of encryption are employed for encryption, namely, encryption for initial data (ring-shaped encryption) and encryption created from the initial data. It is possible to increase the strength for a singular point (initial data), and to increase the encryption strength of the transmitted / received data for a third party.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an encryption device according to an embodiment of the present invention, FIG. 2 is a conceptual diagram showing a relationship between input data and output data, and FIG. Flow chart showing operation. In the figure, (1) is an encryption device, (2) is input data,
(3) is an encryption key usage count setting unit, (4) is an initial data determination unit, (5) is an encryption key setting unit, (6) is an encryption / decryption designation unit, (7) is a gate unit, and (8) is a ring shape. Encryption setting part,
(9) is an encryption unit, (10) is an operation command unit, (11) is a classification unit, and (12) is output data. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

(57) [Claims] In encrypting data, first input data in a predetermined bit unit is used as first initial data, and a first usage count for setting a usage count of a first encryption key based on a pattern of the first initial data. Setting means; and encrypting the subsequent data for each predetermined bit unit up to the use number set by the first use number setting means.
A first encryption unit that performs encryption using the first encryption data, and when the encryption by the first encryption unit is completed, sets the next first input data as the second initial data, and sets the pattern of the second initial data. Means for setting the number of times of use of the second encryption key based on the above, and encrypting subsequent data for each predetermined bit unit up to the number of uses set by the second use number setting means. Second
And a second encryption unit that performs the encryption using the encryption key.