Theory,Method And Application Of Multiset Attack

The design and analysis of block ciphers are the hotspots in the field of information security. Recently people presented Multiset attack which includes Square attack,Collision attack and Integral attack to attack block cipher with Square-like structure.Later Multiset attack is also used to attack block ciphers whose structure is not Square-like. This paper discusses basic theory, methods,application of the Multiset attack .Camellia is one of standard block cipher algorithms in the NESSIE project. Round functions and FL/FL-1functions of Camellia root from E2 and MISTY .But Camellia has SP structure,not S-P-S network of E2; the difference between MISTY and Camellia is the addition of 1-bit rotation to FL/FL-1 function of MISTY.This article changes round functions of Camellia into round function with S-P-S structure and get a variant Camellia ,denoted as Camellia1.We observe that Camellia1 is safer than Camellia against Square attack.Bit-rotation of FL/FL-1functions does not affect the safety of Camellia and Camellia1 obviously,but the layer of FL/FL-1functions affect the safety of Camellia and Camellia1 against Square attack obviously. In 2001,Rijndael is declared to be the new AES.Gilbert H and Minier M presented collision attack on Rijndael whose plaintext block length is 128 bits,which can attack 7 round Rijndael-192/256 with attack complexity 2140.In this paper we analyse collision attack on Rijndael and make use of the shortcomings of Rijndael's key schedule to improve collision attack .The improvement makes 7 rounds of Rijndael-128 be broken successfully and attack complexity is 2124.RC6 is a simple and flexible cipher, which is based on RC5. We apply Square attack to RC6. Operations of RC6 is from different algebraic groups and it uses many data-rotations. Obviously RC6 is not Square-like cipher.Square attack can only attack few rounds of RC6,because the data-rotations of RC6 affact the rules of propagation for active and passive words,which makes Square attack ineffective.We analyse the Square attack against Serpent which is bit-oriented cipher, and the result shows that Square attack on Serpent is weak,because the bit-oriented linear operations interrupt the rules of propagation for active and passive Multiset.