White box block cipher construction method and system based on FeisiteBox Box structure

Abstract

The invention discloses a white box block cipher construction method and system based on a FeisiteBox Box structure. The method comprises the steps that an n-bit plaintext is input, the size na of a block and the iteration processing round number r of a FistelBox structure are set, bit conversion is conducted through a T function, input na-bit bits are converted into nb-bit bits to be output, andna + nb = n; affine transformation is added between the wheels of the iteration processing wheel number, chain connection is performed, the operation of each round is tightly connected with the operation of the previous round and the operation of the next round, the inverse transformation of the affine transformation of the previous round is embedded into the lookup table operation of the round, 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; S1-S2 encryption operation is executed to obtain an encryption result; the system comprises a bit conversion module, an affine transformation module and an operation execution module. According to the invention, an attacker cannot obtain the information of the ciphertext, the password cracking difficulty of the attacker is increased, and the security of key storage is enhanced.

Description

technical field [0001] The invention belongs to the technical field of information security, and in particular relates to a method and system for constructing a white-box block cipher based on a FeisitelBox 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 carried out in an absolutely secure environment. Even if the attacker obtains the plaintext, ciphertext, and encryption algorithm, the attacker cannot know the memory status of the software and the running process. Change. But 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

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