SHA-3算法的抗原象攻击性能优化

通过对SHA-3算法置换函数Keccak-f的线性性质以及缩减轮数的Keccak杂凑函数原象攻击的研究，提出了SHA-3算法的抗原象攻击性能优化设计方案.首先结合Keccak杂凑函数的差分特点和θ置换函数的奇偶性质，分析了基于CP kernel的SHA-3算法原象攻击；然后针对目前实施原象攻击的方法，在θ置换函数运算后异或随机数以打乱其汉明重量，改变CP-kernel的校验性质，阻止攻击者利用中间相遇的方法寻找原象，提高了SHA-3算法的抗原象攻击能力；最后利用VHDL硬件语言实现抗原象攻击SHA-3算法的设计方案，验证了该算法的正确性以及安全性.

Optimization of preimage resistance on SHA-3 algorithm

By analyzing the linear property of Keccak f  permutation functions of SHA-3 algorithm and the round reduced preimage attack of Keccak hash function, an optimization of preimage resistance on SHA-3 algorithm is proposed. Firstly, we combine the differential property of Keccak algorithm and even parity of θ permutation function, and analyze the preimage resistance of SHA 3 algorithm based on CP kernel. Secondly, according to the current preimage attack methods on SHA-3 algorithm, the output of θ permutation function XOR random numbers are used to change Hamming weight and to improve the properties of CP kernel. It prevents an attacker from using meet in the middle method to find the preimage. Finally, the scheme has been implemented with VHDL hardware language. And, the results show that the encryption process has a good performance and high security.