bit slice technology-based dynamic S-box block cipher encryption and decryption method

Abstract

The invention discloses a bit slice technology-based dynamic S-box block cipher encryption and decryption method, which is used for encryption processing of plaintext data, and comprises the following steps of: obtaining to-be-encrypted data and an initial key, from a first round to a penultimate round of operation, each round of operation comprises generalized Feistel structure transformation and key expansion operation, the last round comprises generalized Feistel structure transformation. The generalized Feistel structure transformation comprises first exclusive-or transformation, encrypted S-box replacement, F functions (F1 functions and F2 functions), second exclusive-or transformation and cross transformation on grouped data. The key expansion comprises the steps of sequentially carrying out key S box replacement, one round of generalized Feistel transformation, round of counter XOR and multiple rounds of iteration on the key, and then generating a plurality of sub-keys. According to the method, the S box adopted in the generalized Feistel structure transformation and key expansion process is associated with the corresponding sub-key on the basis of introducing the bit slice technology, and the S box is in a dynamic form in the whole encryption process while it is ensured that the S box can be quickly achieved in software. In addition, the novel dynamic S box construction method not only improves the implementation efficiency of S box replacement in the algorithm encryption process, but also improves the safety of the algorithm by hiding the S box.

Description

technical field [0001] The invention belongs to the technical field of information security encryption, and in particular relates to an encryption and decryption method realized by a dynamic S-box block cipher algorithm based on bit slice technology. Background technique [0002] At this stage, with the continuous development of information technology and the progress of standardization in various countries, symmetric cryptography has been widely used in industrial and commercial fields, and has become the core basis for building secure information systems. As an important branch of symmetric encryption, block cipher plays an extremely important role in information security and has always been a research hotspot. The design of block ciphers has always followed Shannon's "confusion" and "diffusion" principles. As the only non-linear operation in the block cipher algorithm, S-box is very important to the construction of S-box. [0003] Since differential cryptanalysis and li...

AI Technical Summary

Problems solved by technology

However, the attention of this type of algorithm is far less than that of the first type of algorithm, mainly because the existing algorithms of this type, such as Khufu and Blowfish, have some security and practical problems.

Images