The knapsack public key cryptosystem based on np completeness problem and the elliptic curve cryptography ( ecc ) based on discrete logarithm problem ( dlp ) are two significant ones, which plays an crucial role in the development and research of computer cryptology 基于np完全问题的背包公钥密码和基于离散对数问题的椭圆曲线密码(ecc)是两种著名的公钥密码系统,在计算机密码学的发展和研究中具有十分重要的地位。