Research On Proxy Signature Scheme Without Certificate

With the rapid development of the computer science, information security becomes a focus of attention. Cryptography as the core domain in the information security technique, is developing rapidly science C.E.Shannon put forward the communication theory of secrecy system in1949, which also provides a guarantee for the integrity, Non-repudiation, confidentiality and authenticity of message, As a crucial test subjects of Cryptography, digital signature is attracting great attention, particularly on the internet. Different kinds of digital signature was put forward according to the people’s needs, for example, proxy signature, blind signature, group signature, ring signature, threshold signature and so on. This thesis mainly discusses certificateless threshold proxy signature, which applied the threshold technique to proxy signature. And threshold proxy signature is proposed to improve signature security by dispersing the proxy signers’power. The main contents are as follower.1. We first introduce the related research and development of digital signature and threshold proxy signature.2. This paper analyzes a certificateless proxy signature scheme and points out it are vulnerable against two types of adversaries in certificateless cryptosystems, the attack and the new scheme is given,3.A new certificateless threshold proxy signature from pairing is proposed, which combined the certificateless public key cryptography, the verifiable secret sharing technology, the proxy signature signature, In addition, this paper gives the formal proof in random oracle model and the given security model.