结合公钥密码的密钥协商协议

Key agreement protocol combine with public key cryptography

针对目前公钥密码体制的计算代价大,并且需要一个可信的数字证书认证机构才能保证密码体制的安全性,同时证书的维护也是安全方面的隐患等问题,提出一种结合动态公钥密码的密钥协商协议.在认证阶段,将生成的随机数同双方事先约定好的信息串接起来计算其哈希值,把此哈希值和随机数一同发送给对方,哈希函数的单向性使得该随机数能够被正确地传输.在加解密阶段,通过结合对方传输过来的随机数来动态改变公钥算法的密钥对,以实现通信过程中的一次一密.相比传统的通过重新生成大素数来改变密钥对的方法提高了效率,最后通过三种最常用的网络攻击手段验证了协议的安全性.

Aiming at the problems that computational cost of the public key infrastructure is large and a trusted certificate authority is prerequisite to ensure the security of the cryptosystem, the maintenance of the certificate is also the hidden danger, a key agreement protocol combined with a dynamic public key cryptography was proposed. During the authentication phase ,the prior shared information and the random number which generated by sender were concatenated and calculated their hash values, then, the hash values and the random number were transmitted to the receiver, the unidirectional hash function ensures the random number being transmitted correctly. During the encryption and decryption phase, the random numbers transmitted from each other was used to change keys of public key algorithm dynamically. This method achieves the one-time pad in the communication, it makes more efficiency than the method which regenerates the large prime numbers to change the keys. The safety of this agreement is verified by using three techniques which are commonly used on the network attack.