The Research And Realization Of Proactive Secret Sharing

With the rapid development of computer networks, the information has become an important strategy resource of social development, and information security has become a social problem that the world pays the attention to. Threshold secret sharing is one of the important way to save securely important information and data, proactive secret sharing renews every share periodically without changing the secret.This dissertation presents some knowledge that refers to the cryptography. Then it introduces the main idea of threshold secret sharing, and detailedly analyses verifiable secret sharing shceme, secret sharing without the trust and proactive secret sharing. To deal with the problems and deficiency of these schemes, we propose a new scheme of proactive secret sharing which has the following features:1. The scheme has not the trusted center which can prevent the authority cheat. At the same time, the scheme can verify every shareholder's share and find the attackers and misbehaving shareholders. So the scheme improves system's security.2. In order to prevent the mobile adversary from learning or destroying the shares, the scheme renews them periodically, and in such a way that any information learned by the adversary about individual shares becomes obsolete. Hence the scheme enhances system's robustness.3. Some of the shares must be renewed so as to delete the corrupted shareholder and add a new shareholder, therefore the scheme raises system's usability.At last, we use VC++ 6.0 and SQL Server2000 to design a prototype system in windows XP. The result shows that this scheme which has good security and robustness, is right and feasible.