JPH04335730A - Random ciphering communication system - Google Patents

Abstract

PURPOSE:To cipher information by using a completely random number. CONSTITUTION:A sender side of a communication system ciphering transmission information and sending the ciphered information to a receiver side is provided with a 1st random number generating means (equivalent to a ciphering key generating section 121) using an initial value and a chaos equation to generate a completely random number and a ciphering means (equivalent to a logic circuit 122) using a random number generated by the 1st random number generating means to cipher the transmission information. The receiver side of the system is provided with a 2nd random number generating means (equivalent to a ciphering key generating section 221) using an initial value and a chaos equation to generate a complete random number and a decoding means (equivalent to a logic circuit 222) using a random number generated by the 2nd random number generating means to decode the said transmission information into the original transmission information. The ciphering speed is improved and the communication efficiency is improved.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a random encryption communication method for encrypting and transmitting/receiving information during communication.

0002

2. Description of the Related Art Conventionally, information has been encrypted and transmitted in order to prevent information leakage, and the conventional encryption method uses pseudo-random numbers to perform the encryption. However, in this conventional method, the random numbers that are used to encrypt information are only pseudo-generic, so a specific pattern is generated in the cipher, and the cipher can be deciphered from this pattern. Ta.

0003

[Problem to be Solved by the Invention] As mentioned above, since conventional encryption uses pseudo-random numbers, a certain pattern occurs in the created code, and there is a risk that the code may be deciphered from this pattern. there were.

SUMMARY OF THE INVENTION Therefore, the present invention aims to eliminate the above-mentioned drawbacks and provides a random encryption communication system that can perform encryption using completely random numbers. [Structure of the invention]

[0005]

[Means for Solving the Problems] The present invention provides a communication system that encrypts transmitted information and transmits it to a receiving side, and includes a first random number generating means that generates completely random numbers using an initial value and a chaotic equation, and the transmitting side includes an encryption means for converting the transmission information into encrypted information using the random numbers generated from the first random number generation means; a second random number generating means that generates a perfect random number in synchronization with the random number generated on the transmitting side; and a second random number generating means that uses the random number generated from the second random number generating means to convert the received encrypted information into the original transmitted information. The receiver has a configuration in which the receiving side is provided with a cipher restoration means for restoring the cipher.

[0006]

[Operation] In the random encrypted communication system of the present invention, the first random number generating means on the transmitting side generates completely random numbers using an initial value and a chaotic equation. The encryption means converts the transmission information into encryption information using the random number generated by the first random number generation means. The second random number generation means on the receiving side generates perfect random numbers in synchronization with the random numbers generated on the sending side using the same initial value as the initial value on the sending side and a chaotic equation. The cipher restoration means restores the received cipher information to the original transmitted information using the random number generated by the second random number generation means.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a communication system to which the random encryption method of the present invention is applied. 1
2 is a transmitter that encrypts and transmits information, 2 is a receiver that receives the encrypted information and restores it to the original information, and 3 is a line that connects the transmitter 1 and the receiver 2. The transmitter 1 includes a memory 11 for storing transmission information such as plain text, and an encryption unit 1 for encrypting the information.
2. It has a transmitting section 13 that sends out encrypted information onto the line 3 and an initial value generating section 14 that gives an initial value to the encrypting section 12. The receiver 2 includes a receiving section 21 that receives encrypted information on the line 3, a decryption restoring section 22 that restores the received encrypted information to the original information, and a memory 23 that stores the restored information.

FIG. 2 is a block diagram showing a detailed example of the encryption section 12 described above. The encryption unit 12 is the encryption key generation unit 1
21, and a logic circuit 122 that takes the exclusive OR of the encryption key created by the encryption key creation section 121 and the plaintext.

FIG. 3 is a block diagram showing a detailed example of the above-mentioned cipher recovery section 22. The cryptographic recovery unit 22 includes a cryptographic key generation unit 221 and a logic circuit 222 that performs an exclusive OR of the cryptographic key generated by the cryptographic key generation unit 221 and the received cryptographic information.

Next, the operation of this embodiment will be explained. The transmitter 1 reads the plaintext stored in the memory 11 and outputs it to the encryption section 12. At this time, the initial value x0 generated from the initial value generation section 14 is transmitted to the encryption section 12 and the transmission section 1.
given to 3. The transmitter 13 transmits the given initial value onto the line 3. The encryption key creation section 121 of the encryption section 12 creates an encryption key from the initial value x0 and outputs it to the logic circuit 122. The plaintext read from the memory 11 is input to the other input of the logic circuit 122, exclusive ORed with the encryption key, and the result is output to the transmitter 13 as encrypted information. The transmitter 13 transmits the input cryptographic information onto the line 3. The initial value and cryptographic information on the line 3 are received by the receiving unit 21, and the cryptographic information is received by the cryptographic recovery unit 2.
2 is output. The encryption key generation unit 221 generates an encryption key from the initial value received by the reception unit 21 and sends it to the logic circuit 22.
Output to 2. On the other hand, the encrypted information received by the receiving unit 21 is input to the other input of the logic circuit 222, and the exclusive OR is performed with the encryption key to restore the original plaintext. The plaintext restored in this way is stored in the memory 23.

Next, the principle of operation of the encryption key generation section 121 or 221 will be explained in detail. xn+1 =4xn (1
-xn )...(1) shows the simplest chaotic equation. However, n is a natural number. The encryption key generation unit 121 or 221 creates random bit information in units of bytes using the chaos equation, and this bit information is called an encryption key, and the plaintext is encrypted using this as described above. When the initial value x0 given to the encryption key generation units 121 and 221 is substituted into the chaotic equation shown in (1) above, the values of x1, x2, etc. are obtained one after another, and these values take completely random values. In other words, it behaves in a chaotic manner. However, 0<x0<1. Here, find the number of bytes of the plain text to be encrypted. For example, if this is 1 byte, take the value of the 8 decimal places of x1, x2, x3, and if the value of each digit is 0 to 4, then The digit is set to 0, and 5
When the number is 9, the digit is set as 1 to create an 8-bit code string. For example, suppose x0 = 0.52715634, and by substituting this into the chaotic equation shown in (1), x1, x
2, x3... are found in sequence. In this case, x1 =0.
99705013, x2. =0.01176467. Next, if the numerical values constituting each digit of x1 and x2 are 0 to 4, they are converted to "0", and if they are 5 to 9, they are converted to "1" to create an 8-bit code string. That is, x1 to 11101000
occurs, 00011011 is created from x2, and these are called encryption keys.

[0012] On the transmitter side, the cryptographic key created in this manner is exclusive ORed with the plaintext to be transmitted in the logic circuit 122, and the plaintext is encrypted. To describe a specific example of this encryption for the above example, if the plaintext is 00110101, the encryption key is 111010.
If it is 00, the exclusive OR of these two results in 11011101, which becomes the cipher for the plaintext. The code created in this way is sent to the transmitter 13
It is sent to the receiving section 21 via the receiving section 21, and further sent from the receiving section 21 to the encryption restoring section 22. The encryption key creation section 221 of the encryption recovery section 22 creates an encryption key that is the same as the encryption key created by the encryption key creation section 121 of the transmitter, and supplies this to the logic circuit 222 . The logic circuit 222 uses the encryption key and the receiver 21
The plaintext is recovered by performing an exclusive OR with the cipher received at . In the above example, when the cipher is 11011101, the encryption key is 1101000, and the exclusive OR of the two results in 00110101, which restores the plaintext. Note that the encryption key used when encrypting a certain plaintext is the same as the encryption key used when restoring the plaintext from the cipher created in this way.

FIG. 4 is a diagram showing the communication procedure from the transmitter 1 and the transmitter 2 described above in association with the numerical values obtained from the chaotic equation shown in (1) above. First, transmitter 1
sends the initial value x0 to the receiver 2. Next, the first byte of plaintext is converted into ciphertext based on the numerical value x1 created by transmitter 1, and this is sent to receiver 2. Receiver 2 restores the received ciphertext based on the numerical value x1 created by receiver 2 to obtain the first byte of plaintext. The same applies below.

According to this embodiment, since completely random numbers created from a chaotic equation are used when encrypting the plain text to be transmitted, it is possible to eliminate the occurrence of a predetermined pattern in the encryption. , the cipher can be prevented from being decrypted unless the chaotic equation and the initial value (which changes each time) are known. Furthermore, since this example uses the simplest chaotic equation, the encryption speed is fast and communication efficiency can be improved.

[0015]

As described above, according to the random encryption communication system of the present invention, it is possible to perform encryption using completely random numbers.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a communication system using a random encryption communication method of the present invention.

FIG. 2 is a block diagram showing a detailed example of the encryption unit shown in FIG. 1;

FIG. 3 is a block diagram showing a detailed example of the encryption recovery unit shown in FIG. 1;

FIG. 4 is a diagram showing a communication procedure of the communication system shown in FIG. 1;

[Explanation of symbols]

Claims (1)

[Claims] Claim 1: A communication system that encrypts transmitted information and transmits it to a receiving side, comprising: a first random number generating means that generates a completely random number using an initial value and a chaotic equation; The transmitting side is equipped with an encryption means for converting the transmission information into encrypted information using the generated random numbers, and the transmission information is generated on the transmitting side using the same initial value and chaos equation as the initial value of the transmitting side. a second random number generation means that generates a perfect random number in synchronization with the random number; and an encryption recovery means that uses the random number generated by the second random number generation means to restore the received encrypted information to the original transmitted information. A random encrypted communication system, characterized in that the receiving side is provided with: