S-box parametric design method and storage medium based on bit-and operation

Abstract

The present invention relates to the technical field of communication encryption. The present invention discloses a S-box parameterized design method and storage medium based on bit-and operations. The method includes: randomly selecting F for the selected S-box specification n 2 n‑2 → F 2 The Boolean function f 1 , f 2 , for the n-bit input data of the S box, traverse {0,1,...,2 n ‑1} The n-bit binary vectors corresponding to all integer values, for the n-bit binary vectors corresponding to any integer value i, first perform multiple rounds of n-branched generalized Feistel structure round transformation, and then perform nonlinear transformation, and calculate the result Perform bit combination to obtain the value of the S-box of nn specification in the integer i, and finally output the S-box. The parameterized S-box obtained by the present invention has excellent cryptographic properties, and at the same time has low software and hardware implementation costs, and can provide abundant choices for parameterized obfuscation components of componentized variable cryptographic algorithms.

Description

technical field [0001] The invention relates to the technical field of communication encryption, in particular to a bit-and operation-based S-box parameterized design method and a storage medium. Background technique [0002] The invention relates to the technical field of communication encryption, in particular to a parametric design method of an obfuscation component S-box in symmetric cryptographic algorithms such as block ciphers, sequence ciphers, and hash algorithms. [0003] The design of existing symmetric cryptographic algorithms at home and abroad mainly adopts the "confusion" + "diffusion" principle proposed by Shannon in 1949. The relationship is so complex that an attacker cannot get any information about the plaintext from the ciphertext, or any information about the key from the plaintext pair. [0004] The "confusion" component generally uses a non-linear substitution S box (Substitution Box). The S-box first appeared in the block cipher algorithm Lucifer, ...

AI Technical Summary

Problems solved by technology

In order to ensure the security strength of the cryptographic algorithm and its components, if the componentized variable cryptographic algorithm realizes the parameterization of the algorithm components by replacing the non-linear fixed table, the off-line preset method will be the main method, in order to achieve the change amount of the security strength setting , the number of S-boxes that need to be pre-stored is generally large, and there are two weaknesses: one is that it occupies a large amount of storage resources of the cryptographic algorithm bearer device, and the other is that it cannot support online dynamic configuration

[0007] In terms of key-dependent variable S-boxes, RC4, Twofish and other algorithms adopt the design method of key-dependent S-boxes, but there are S-boxes that rely on random key exchange or multi-round iterations, and their cryptographic properties are uncontrollable. , can not give a theoretical circle with practical guiding significance and other design defects

[0008] In general, there are few researches on the S-box parametric design method in the current public information, and it is necessary to further improve its characteristics and capabilities in supporting online replacement configuration, safety and controllability, etc.

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