Biclique Analysis Of Several Typical Lightweight Cryptographic Algorithms

The Biclique structure can successfully attack ESF and LBlock.So far,cryptographic researchers have evaluated the ability of ESF and LBlock algorithms to various attacks.Research shows that the relevant key differential analysis,impossible differential analysis and truncation impossible differential analysis of ESF cipher algorithm,as well as the impossible differential analysis and integral analysis of LBlock algorithm have achieved good results.In this paper,we found that the key extension algorithms in the light block cipher ESF and LBlock are not secure.Biclique analysis method is engaged to attack ESF and LBlock cipher algorithms,and the results verify it.The main work is as follows:1?ESF is a lightweight block encryption algorithm with generalized Feistel structure.It is an improved algorithm based on LBlock algorithm.In this paper,the Biclique analysis is used to attack ESF on all rounds.First,the whole key space of the algorithm is divided into multiple sub-key sets.Then,a 4-D Biclique structure of 5 rounds is constructed.Thereafter,the appropriate internal matching variables are selected and the values of the two directional matching variables are calculated.The attack result of Biclique analysis is the best result of attack on ESF algorithm so far.The paper also makes some improvements to the diffusion of the key scheduling part of ESF algorithm.2?The Biclique analysis is used to carry out full-round attack on LBlock.The attack is also carried out from the plaintext direction,and the specific process is similar to the Biclique attack of ESF algorithm.This attack constructs a 4-dimensional Biclique structure with 8 rounds,then selects the appropriate internal matching variables and calculates the values of the two directional matching variables,deletes the mismatched keys,and finally calculates the complexity required for the whole attack process.In the end,the results show that the ESF and LBlock key expansion algorithms have poor diffusion and certain potential security problems.As an effective cryptanalysis method,the Biclique attack method has a better attack effect on some algorithms than the differential analysis and linear analysis.