Implementation method of SM4-like cryptographic algorithm

Abstract

The invention discloses an implementation method of an SM4-like cryptographic algorithm, which belongs to the technical field of cryptography. The method comprises the following steps of: grouping file data to be encrypted to generate a plurality of pieces of data, and dividing the plurality of pieces of data into a first type of input data and a second type of input data; performing cyclic shiftoperation on at least two branch data in the first type of input data to obtain preprocessed first type of input data; performing first exclusive-OR operation on the preprocessed first type of input data, and sequentially inputting the first type of input data into an S box for change and P replacement to obtain first output data; and performing a second XOR operation on the first output data andthe second type of input data to obtain an intermediate state, and performing iteration on the intermediate state to obtain a ciphertext. The cyclic shift operation is introduced before XOR of the first type of input data, so that the relative positions of the same data entering the S box for three times are different, and the diffusivity of the algorithm is improved.

Description

technical field [0001] The invention relates to the technical field of encryption, in particular to an implementation method of an SM4-like encryption algorithm. Background technique [0002] With the rapid development of electronic computer and communication technology, the Internet has penetrated into many fields. The information system established on this basis has brought great changes to people's daily life and work, but at the same time, the open environment has also brought security threats to the information system. Information security technology is an important means to maintain information confidentiality, integrity and reliability, and it includes all measures to protect information from illegal modification, destruction and disclosure. Cryptographic technology is the core of information security technology, which includes the design and analysis of cryptographic algorithms, identity authentication and digital signature, key management and other security areas. ...

AI Technical Summary

Problems solved by technology

[0004] The structure of the SM4 algorithm is designed based on 32-bit words and 8-bit bytes, but at present, it is impossible for differential, zero-correlation linear, integral, etc. to pose a threat to the security of the low-round SM4 algorithm

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