HYBRID APPROACH FOR VERIFIABLE SECRET SHARING USING CHINESE REMAINDER THEOREM

Abstract

ABSTRACT It is not always in the best interests to have a single person in control of the data or any sensitive information. This has led to the need for secret sharing schemes. A secret sharing scheme is a method of distributing a secret among a group of users, requiring a cooperative effort to determine the key. This thesis presents a hybrid approach for verifiable secret sharing. Our algorithm shares secret among shareholders where shareholders are also divided into different levels. Thus proposed work includes multi-level secret sharing. Secrets can be recovered within the level or inter level secret sharing is also possible. Shareholders of higher level can contribute their shares in lower levels for secret recovery. To make the scheme verifiable we have used hashing because other schemes depends on hard to solve number theoretic problems or uses any additional information which in turn increases overhead of the protocol. It stands against dishonest dealer and dishonest shareholders. Here we have used one way hash function so that shareholders can verify the shares obtained from the dealer and dealer can also verify shares before accepting it from shareholders before secret reconstruction. There exist many dishonest strategies. VSS is a way to deal with one of the existing dishonest strategy. In VSS schemes neither dealer nor any participant will be able to distribute/submit invalid shares.