Threshold Secret Sharing Scheme And Its Application In Digital Signature

Abstract:With the extension of information technology's application field, information security becomes more and more important. Cryptology, as one of the core technology of information security, has been becoming a worldwide hot topic. In cryptography for solving the problem of information security cryptography technology provides such as in secret communication can through the encryption method to realize the information security of practical techniques.However, due to the key security problems are the core issue of encryption technology, but the key security requirements of data security off than the general higher, if only to protect the encryption key is difficult to achieve its security of confidential requirements. The key management's problems directly affect the safety of a communication system, the effective management of the key problems in the current cryptography becomes an important issue.Threshold technique and forward safety technique are two kinds of important methods of key safekeeping of security. Currently,in cryptography threshold techniques typically include the threshold secret sharing technique and threshold digital signature technique:Threshold technique means that the key was to take care of by many numbers together.Through secret sharing scheme, even if individuals or the minority numbers'secret share divulges , there will be no affection to the key security of overall system. Keep secret use secret sharing, on the one hand is in favour of preventing excessive concentration of power which is abused; on the other hand, it can guarantee the security and integrity of the secret. The main idea of the fowrard safety technique is to partition the secret key's life into certain times,in the end of each time the signaturer uses a single patterns to receive a new secret key which will be used in next time from the current time's secret key,and safely delete the no longer use secret key. But the public key in the key's life cycle is not to change to ensure all the effectiveness of signature before the current time .Threshold secret sharing seheme have guaranteed the key's seeurity in these areas,and become the hot reseaerh spot of the security domain.Securitial threshold secret sharing scheme and its application in digital signature are researched in this thesis. First of all, this system introduces the threshold secret sharing system, the knowledge in several classic of the threshold secret sharing scheme, and then analys the security based on different cryptosystem threshold secret sharing scheme, last, prior to the security detail introduces the first threshold secret sharing scheme secure digital signature to the application of an analysis of the two former to secure threshold digital signature scheme based on the credibility of the Center, which is based on forward-secure threshold digital signature scheme.The program is supported by a trusting center, coupled the with use of Z and the number of polynomial decomposition problem to achieve a system of forward-secure threshold.The system is easy to implement, and members have limited computation, even if the attacker has obtained the key in a certain period can not threat the other period's secret key, This system has high-performance security, in practice, has broad application prospects.