Security research with Square attack to a variant Camellia cipher

This paper investigates the relation between the choice of S-boxes and Square attack.A variant Camellia,which uses only a single S-box instead of four,is proposed.The security of the variant Camellia against Square attack is studied in detail.Result shows that it needs only 28 chosen plaintexts to recover a byte of the 6th round-key of variant Camellias,while the original Camellia needs either 28 chosen plaintexts to recover a byte of the 6th round-key and a byte of some constant or 216 chosen plaintexts to recover a byte of the 6th roundkey.Furthermore,Square attacks on other round-reduced variant Camellia are proposed,and the time complexity of 11-round attack is reduced from 2^(250)to 2^(225.5).The weaker variant Camellia indicates that the choice of S-box and the order of different S-boxes have influence on Square attack.

对于5轮Camellia密码的Square攻击

讨论了Square方法对于Camellia密码的攻击 .结果表明 ,Square方法是攻击Camellia密码最有效的方法之一 .Camellia密码是欧洲NESSIE密码计划中 ,分组密码候选加密算法之一 .它是 1 2 8比特密码分组 ,支持 1 2 8、1 92和 2 5

变种Camellia对Square攻击的安全性

讨论了Camellia1对Square攻击的安全性,并就FL/FL-1函数对Camellia与Camellia1抗Square攻击能力的影响进行了分析.结果表明Camellia1对Square攻击的安全性远大于Camellia,FL/FL-1函数中的比特循环移位运算对Camellia及Camellia1抗Square攻击的能力并无明显影响。