The Research And Realization Of Secret Sharing In Hierarchy

With the development of network technology, more and more information transfer by network. Encrypting is the efficient way to protecting information. The key is the base of Encrypting information. And the key manage system can effectively protect the key. The aim of research of secret sharing in hierarchy is to find a suitable scheme to manage the key in hierarchy that can make the information transfer safety in network.In this thesis we firstly introduce the development of the secret sharing in hierarchy. Then we find problems about the key management from some scheme of secret sharing in hierarchy that proposed these years. To resolve these problems, we propose a new scheme of secret sharing in hierarchy bases on the ELGAMAL algorithm. And this scheme has the following features:1.Using the Shamir's (t,n) threshold scheme to manage the key of group in hierarchy.If the number of the shadows are more than t, the members of group can reconstruct the key by these shadow.This method resolves the problem that the key can't be reconstructed if some shadow lost.2.This scheme has the ability of reusing the shadows of key. So the shadows have not to be renewed when the key has been reconstructed.In this thesis we use VC++ 6.0 and SQL Server2000 to design a prototype system based on this scheme. The result shows that our scheme has good validity and security. At last, we summarize our dissertation and expect the future of secret sharing in hierarchy.