一种对优化的NTRU体制的可解密密文分析

Proos利用NTRU的解密出错的缺陷提出了一种对NTRU原始算法的可解密密文攻击1].为了增强NTRU原始算法的速度和效率,文2]提出了NTRU的优化算法.但是,Proos并未对NTRU的优化算法给出相关的密码分析.文中指出了Proos所提出的可解密密文攻击对NTRU优化算法的部分情况仍然有效,并指出在文2]所给出的优化的NTRU参数选取中当N =503时可能会泄漏部分私钥信息.

A Decipherable Ciphertext Attack on Optimized NTRU

Proos presents a decipherable ciphertext attack on the primitive NTRU based on its property that the NTRU does not provide a perfect decryption. In order to increase the speed and efficiency of the NTRU public key cryptosystem, the author of the paper 2] described the optimization for the NTRU cryptosystem. However, Proos did not give the relative analysis of the optimized cryptosystem. In this paper, we conclude that the optimized cryptosystem will be attacked under definite circumstances using decipherable ciphertext attack presented by Proos. And we give the analysis of decipherable ciphertext attack on the optimized NTRU. Furthermore, we conclude that there is possibility that partial information leakage of the secret key will happen when we choose N=503 in the parameter advised in paper 2].