Application Of Mixed-Integer Linear Program In The Security Analysis Of Blockcipher

With the development of the cryptology,many automatic tools of cryptanalysis come into beings,and gradually become the main method for cryptanalysis and the security analysis.Mixed-integer linear program is a typical problem of operational research.In 2011,it was firstly applied in cryptanalysis,after which it gradually becomes a frequently-used tool of automatic cryptanalysis.This dissertation mainly considered the two block ciphers: PICO cipher and RECTANGLE cipher.Until now,the security of PICO cipher toward impossible differential cryptanalysis hasn't been evaluated.Toward zero-correlation linear cryptanalysis,the designer only gave a 4-round zero-correlation linear approximation.For RECTANGLE cipher,the designer proposed that there are 8-round impossible differentials,and the zero-correlation linear cryptanalysis hasn't been proposed.With the automatic tool of mixed-integer linear program,we analysed the security of the two ciphers against impossible differential cryptanalysis and zero-correlation linear cryptanalysis.The main results are as follows:(1)The security analysis of PICO cipher against impossible differential analysis and zero-correlation linear analysis.We firstly built an impossible differential model for this cipher,and found 33 8-round non-trival impossible differential trails.With 15 of them we built a truncated impossible differential distinguisher and made a key recovery attack.Then we applied the MILP model based on zero-correlation linear analysis and found 2217 7-round non-trival zero-correlation linear trails,with 63 of which we built a muti-dimentional zero-correlation distinguisher and made a key-recovery attack.(2)The security analysis of RECTANGLE cipher against impossible differential analysis and zero-correlation linear analysis.We summarized a proposition of the translate of RECTANGLE and gave a proof.With this proposition we can reduce the search space and improve the result.We built an impossible differential model for RECTANGLE,and found 672 8-round non-trival impossible differential trails.With the MILP model of zero-correlation linear analysis we found 208 8-round non-trival zero-correlation linear trails,and gave the method of key-recovery attack.