Research On The Cryptosystem Related To Secret Key Security

With the advance of the technique about computer network, all kinds of network sevices have soaked in many aspects of people's life. On the one hand, they bring much convience and advantage to people's actions. On the other hand, they bring an unparalleled threat. The confidentiality, integrity and availability should be satisfied because some important data are transferred by network. The technique of cryptology and information security is an effective means to deal with this problem.The security of secret key is a very important and central problem in the field of cryptology and information security. Once a secret key is exposed, all cryptological operations related to this secret key are insecure no matter how strong the cryptological algorithm is. Therefore, the exposure of secret key threatens the security of cryptosystem greatly. How to reduce the probability of secret key exposure and how to reduce the damage by means of cryptography when secret key exposure happens are very significant research work. Secret sharing and threshold cryptography, forward secure cryptography, key-insulated cryptography, intrusion-resilient cryptography and secure key retrieval protocol are all important work related to secret key security.The main idea of secret sharing and threshold cryptology is to divide the secret key into several shares and store them in multiple severs respectively. When we need to construct this secret key or do some cryptological operation related to this secret key, only no fewer than a certain number of severs can complete this work. Any severs group fewer than the certain number can't computer this secret key. This method reduces the probability of secret key exposure directly, which is an important offset in cryptography. One of the important research objects is secret redistribution protocol, which deals with the problem of how to redistribute the secret that has been shared in a group of shareholders to a new group of shareholders correctly. Secret redistribution protocol must be run without any trusted dealer and without reconstruction of the secret. Unfortunately, there is a problem in present verifiable secret redistribution protocols, that is, these...