Symmetric encryption and decryption method, and symmetric encryption and decryption system

Abstract

A symmetric encryption and decryption method and a symmetric encryption and decryption system are provided. The symmetric encryption and decryption method includes the following steps that: data to be processed, keys and first random numbers are provided; first computation and first linear computation are performed on the data to be processed, the keys and the first random numbers, such that first data are obtained; the first linear computation and second computation are performed on the first random numbers, such that second data are obtained; nonlinear computation is performed on the first data, such that third data are obtained; the first computation and second linear computation are performed on the third data and the second data, such that encryption and decryption data are obtained; the nonlinear computation includes the step that initial SBOX is provided; the second computation is performed on the first random numbers, such that fourth data can be obtained; the first computation is performed on the initial SBOX and the fourth data, such that fifth data can be obtained; the locations of elements in the fifth data are adjusted according to the first random numbers, such that new SBOX is obtained; and nonlinear byte data corresponding to the first data are selected from the new SBOX and are adopted as the third data. With the symmetric encryption and decryption method and the symmetric encryption and decryption system of the invention adopted, the security and efficiency of encryption and decryption can be improved.

Description

Technical field [0001] The present invention relates to the technical field of information processing, in particular to a symmetric encryption and decryption method and a symmetric encryption and decryption system. Background technique [0002] In order to ensure message security, the message needs to be encrypted and decrypted. Commonly used encryption and decryption technologies include symmetric encryption and decryption technology and asymmetric encryption and decryption technology. Among them, in the symmetric encryption and decryption technology, the data sender encrypts the plaintext (original data) and the encryption key together to make it a complex ciphertext and sends it out; after the recipient receives the ciphertext, Using the same key and the reverse process of the encryption process to decrypt the ciphertext, it can be restored into a readable plaintext. Symmetric encryption and decryption has the advantages of open algorithm, small amount of calculation, fast en...

AI Technical Summary

Problems solved by technology

[0018] 1) The non-linear arithmetic unit 70 needs to include a memory to store the new SBOX, thereby increasing the area of ​​the hardware, which is not conducive to the miniaturization of the encryption and decryption device;

[0019] 2) Before each encryption and decryption, the value of the corresponding SBOX needs to be recalculated according to the new random number, thus requiring additional clocks and increasing the number of clocks for encryption and decryption;

[0020] 3) The non-linear arithmetic unit 70 has a single implementation method, which is prone to side-channel signal attacks and has poor security;

[0021] 4) Different symmetric encryption and decryption systems cannot achieve compatibility

Images