Verifiable Secret Sharing And Proxy Signature

Verifiable secret sharing is an important tool in the design of cryptography protocols. Proxy signature is a useful method in delegating signer's signing capability. The research of this dissertation focuses on verifiable secret sharing (publicly verifiable secret sharing) and proxy signature.Following are the results of the thesis:1: A survey on verifiable secret sharing especially some protocols is given.2: Analyzing the drawback of some main verifiable secret sharing protocols, we propose a new verifiable joint secret redistribution protocol.3: By studying on publicly verifiable secret sharing, a proof of knowledge of a double discrete logarithm based on elliptic curves and a publicly verifiable distributed key generation protocol are given.4: A survey on proxy signature and a nominative multi-proxy signature scheme are given.5: Applying the verifiable joint secret redistribution protocol, two classes threshold proxy threshold signature scheme based on ECC(elliptic curves cryptosystem) is proposed.6: Applying the proof of knowledge of a double discrete logarithm based on ECC and the publicly verifiable distributed key generation protocol, threshold proxy blind signature scheme based on ECC and publicly verifiable distributed proxy blind signature scheme are given.