Pseudorandom sequence generation method and pseudorandom sequence encryption method

Abstract

The invention discloses a pseudorandom sequence generation method, which comprises: acquiring elements from a value range of {1,2,...,2<e>-1}, wherein e is a positive integer greater than 2; and generating a sequence in a linear recurrence mode based on the elements and a primitive polynomial over Z / (2e-1), wherein in the initial state of the sequence, at least one element is relatively prime to 2<e>-1. The method can generate the pseudorandom sequence with equivalent entropy preservability, rich nonlinear structures and quick periodical growth, balances sequence period and the number of sequence inequal circles, greatly reduces the complexity of sequence source processing in algorithm design and makes the sequential cipher system simple and safe. The invention also provides a method for building a stream cipher system, which comprises: generating the pseudorandom sequence with equivalent entropy preservability by the previous method and using the pseudorandom sequence as a core sequence source; and in a key word combination process, evenly distributing key output by using the elements or operation and providing a simple, safe and high-efficiency sequential cipher algorithm for guaranteeing data security.

Description

technical field [0001] The present invention relates to the technical field of information security. Specifically, the present invention provides a pseudo-random sequence generation method and an encryption method that output bit equivalent entropy. Background technique [0002] The selection and design of pseudo-random sequence sources is a core content in the design of sequence ciphers. The sequence source design based on the shift register mostly considers the m-sequence on the binary field GF(2) or the general finite field GF(2 n ) on a linear recursive sequence. However, there are obvious and multiple linear relationships among the bits of such sequences, which makes sequence ciphers based on them vulnerable to correlation attacks. In addition, the method of linear recursion and simple nonlinear transformation method also make it possible to establish low-degree equations by algebraic attack. Therefore, with GF(2 n ) as a sequence source, it will lead to the difficu...

AI Technical Summary

Problems solved by technology

When e=8, the size of the register must reach 456 bits; when e=16, the size of the register needs 784 bits; when e=32, the size of the register is 1056 bits; therefore, Z / (2 e ) on the primitive sequence is very unsatisfactory

[0006] (2) The weight sequence does not have algebraic equivalence

However, masking weaknesses in sequence sources is always a concern, as is the case with GF(2 n ) on linear feedback shift register sequence cryptosystem attempts to conceal the linear nature of the source sequence are always unsuccessful

[0008] In addition to the above two points, for an odd prime number p, because modulo p e The difficulty of operation implementation, Z / (p e ) The implementation efficiency of linear recursive sequence is far from meeting the actual needs

Images