混合密码SCB算法的密钥恢复攻击

针对SCB (senior cross breed)算法序列部分设计的安全问题, 在已知序列部分生成的密钥流的情况下,用 O(2⁴⁴)的计算复杂度恢复算法的种子密钥。为得到序列部分攻击所需要的密钥流, 基于单比特随机故障模型, 对SCB算法分组部分进行了差分故障攻击, 当引入640次故障时, 攻击算法成功率可以达到99.4%。恢复算法256 bit种子密钥需要的计算复杂度为O(2⁴⁴)。

Key Recovery Attack on Hybrid Cipher SCB Algorithm

According to the flaws in the design of the stream cipher part of SCB (senior cross breed) algorithm, the initial key could be recovered with the computational complexity of O(2⁴⁴) if the key stream of the stream cipher was known. To acquire the keystream of the stream cipher, a differential fault attack was proposed by using word oriented fault model for one bit random fault. When 640 faults were induced, the success rate could achieve 99.4%. The computational complexity to recover the 256 bit key was O(2⁴⁴).