Construction method and system of white-box block cipher based on feistelbox structure

Abstract

The invention discloses a white box block cipher construction method and system based on a FeistelBox structure. The method comprises: inputting n-bit plaintext, setting a block size n a , the number of iterative processing rounds r of the FeistelBox structure, use the T function to perform bit conversion, and convert the input n a bit bit to n b bit bit output, where n a +n b =n; add affine transformation between the rounds of the iterative processing rounds, and perform chain connection, the operation of each round is closely connected with the operation of the previous round and the next round, by converting the affine of the previous round The inverse transformation of the transformation is embedded in the lookup table operation of this round, and then the affine transformation of the previous round is applied to the result of the lookup table, and the affine transformation layer adopts the reversible affine transformation matrix; the encryption operation of S1-S2 is performed to obtain Encryption result; the system includes a bit conversion module, an affine transformation module and an execution operation module. The invention makes it impossible for the attacker to obtain the information of the ciphertext, increases the difficulty for the attacker to crack the password, and strengthens the security of key storage.

Description

technical field [0001] The invention belongs to the technical field of information security, and in particular relates to a white box block cipher construction method and system based on a FeistelBox structure. Background technique [0002] With the rapid development of networks and computers, information is closely related to everyone, and people pay more and more attention to the protection of information. How to effectively protect their personal information has become a problem that everyone pays attention to. In traditional cryptography, the encryption environment is performed in a black-box environment by default. In the black box environment, it is assumed that all encryption algorithms are performed in an absolutely safe environment. Even if the attacker obtains the plaintext, ciphertext and encryption algorithm, the attacker cannot know the running memory state of the software and the running process. Change. However, in reality, attackers can still obtain softwar...

AI Technical Summary

Problems solved by technology

However, fast key mixing and efficient key scheduling functions for small-block ciphers are largely unknown

Images