Extended Algebraic-Side Channel Attack and Its Application
Wang Jin-hui · Dianzi xuebao · 2013
Algebraic-side channel attack(ASCA) was proposed by Renauld et al.which combines algebraic attack and side channel attack.The current research of ASCA mainly focuses on the 8-bit implementation of a block cipher.For 64-bit platform,there is no such research.This paper gives an extended algebraic side channel attack which represents the leaked information as explicit function of the key bits.Compared with the original ASCA,the extended ASCA needs less leaked information.As an application,we give an extended ASCA on LBlock light weight block cipher:For LBlock implemented on 64-bit platform,if the Hamming weight of the output of 1-3 round of LBlock can be obtained without error,then with 35 known plaintexts,an equation system concerning the 80 bit maser key can be set up;on a general PC,the 80 bit master key can be obtained in a minute by using Magma mathematical software v2.12-16 to find the Groebner basis.This is the first ASCA attack on LBlock,which shows that the method of moving form 8-bit platform to larger devices suggested by Renauld et al.to prevent ASCA is not enough.