Block ciphering method based on random function to resist against known plaintext-ciphertext pair attack

Abstract

The invention belongs to the field of information security, and relates to a block ciphering method. The block ciphering method is constructed by a random function. The cryptographic (encryption) algorithm is uncertain and random, when the random function is used to encrypt, the concrete form of the function is determined by a secrete key which also determines the concrete form of the function and is an input parameter of the function, so an analyzer cannot think about the whole situation. By virtue of the design, a cipher analyzer cannot determine the algorithm when the analyzer does not know the secrete key, thus the analyzer cannot effectively analyze the cipher through the known plaintext-ciphertext pair.

Description

technical field [0001] The invention belongs to the field of symmetric cryptography, and relates to a group encryption method against known plaintext and ciphertext pair attacks. Background technique [0002] Existing encryption systems are all based on definite encryption algorithms. Although they are convenient, widely used and standardized, and easy to be widely evaluated, these algorithms have a very clear and fixed structure, only plaintext, key and Some parameters are changed, and they all participate in the calculation under the fixed algorithm framework to obtain the ciphertext. These constraints on the degree of freedom of the cryptographic system also have a negative impact on the security of the cryptosystem. A large number of cryptanalysis is also aimed at the situation determined by the algorithm, and these analyzes have assumed that the algorithm is already known. We can think of a deterministic algorithm as a deterministic function. If the function correspon...

AI Technical Summary

Problems solved by technology

So here we use the key k to determine A