Research On Verifiable Secret Sharing And Its Application

Verifiable secret sharing is a very important part of modern cryptography. Using the verifiable secret sharing to store secret, on the one hand it is propitious to prevent the right to be over-concentration so as to be abused, on the other hand it can guarantee the security and integrality of the secret, verifiable secret sharing is also one of the important bases of fair exchange protocol, therefore the research of the verifiable secret sharing have the important application value. At present, many verifiable secret sharing schemes have been proposed, but there is great room for improvement both in security and efficiency. This paper study the verifiable secret sharing deeply on these issues above and design a fair exchange protocol based on publicly verifiable secret sharing.Firstly, two systems of verifiable secret sharing are researched and improved which are widely used. Using the message blind technology, a verifiable secret sharing scheme based on shamir system is proposed and analyzed; according to the dishonest behavior may occur in the Iftene'scheme, a verifiable secret sharing scheme based on Asmuth-Bloom system is proposed, describe the construction process of the scheme and the security and the efficiency analysisSecondly, a verifiable multi-secret sharing scheme based on Chinese Remainder Theorem is proposed. By using the Chinese Remainder Theorem, multiple secrets are packaged into a single secret, simplify the operation of multi-secret sharing. The participant create the shares themselves, avoid using of the security channel, and also the shares can be use many times without update. RSA and discrete logarithm guarantee the security of the scheme. At last, the safety and efficiency of the scheme are analyzed. Finally, a fair exchange protocol is proposed based on publicly verifiable secret sharing. The new protocol is realized by introducing distributed off-line semi-trusted third parties and prevents the one party conspiring with semi-trusted third party to cheat the other effectively. While analysis the fairness, privacy, security, effectiveness, timeliness and anti- conspiracy of the protocol.