Further Study Program Signcryption Undocumented

With the rapid developments of the network technology and computers, the speed of information transmission is becoming more and more fast. When People enjoy the huge benefits that network brings, they also face a serious of informational securities. Information security is related to the security of a country and the nation’s prosperity and the war’s victory. The core content of information security is how to ensure information confidentiality, authentication and integrity. Using signature and encryption is the key to realize the Information security. Signcryption is an important component of information security, which plays important role in information security and data confidentiality. In1997, Zheng first propose a signcryption scheme, where it finishs the signature and encryption simultaneously. Since signcryption saves more computational cost than the traditional signature encryption scheme, that means it has high efficiency. And later scholars have conducted in-depth research on Signcryption Scheme. In order to solve the certificate management problem caused by the traditional public key cryptosystem, Shamir proposed the ID-Based public key cryptosystem in1984,which had the problem of who deposited the secret key, Al-Riyami and so on proposed the certificateless public key cryptosystem in2003. The first certificateless signcryption scheme is proposed in2008. Combined the certificateless cryptography scheme with signcryption scheme not only have high efficiency, but also inherit the advantages of certificateless cryptosystem.This thesis focurs on certificateless signcryption, the main research of this paper’s results are as follows:1. Analyzed the F-Z scheme and L-X scheme, and found that t the two schemes have forged, which both can not stand up to the first enemy.Then we propose a new certificateless signcryption based on the Liu’s scheme. In the new scheme, we give the safety analysis; as a result, we found our scheme satisfied Public Verifiability and Unforgeability.2. On the basis of the Waters’s signature scheme, we present a high efficient certificateless signcryption, in which scheme we analyze its security on the use of the random oracle model. In the new scheme we only use3bilinear pairings, at the same time, we found our scheme satisfied Public Verifiability and Unforgeability.