A dealer-free and non-interactive dynamic threshold secret sharing scheme has been proposed by Harn et.al., in 2015. In this scheme, a (t; n) secret sharing scheme in secret reconstruction phase can turn into a (m;n) scheme in secret reconstruction phase, where m is the number of participanting shareholders. It has been claimed that the secrecy of shares and the secrecy of the secret are uncond...

Secure communication has become more and more important for system security. Since avoiding the use of encryption one by one can introduce less computation complexity, secret sharing scheme (SSS) has been used to design many security protocols. In SSSs, several authors have studied multipartite access structures, in which the set of participants is divided into several parts and all participant...

Secret sharing schemes divide a secret among multiple participants so that only authorized subsets of parties can reconstruct it. We show that SETUP (Secretly Embedded Trapdoor with Universal Protection) attack can be embedded in secret sharing schemes that employ enough randomness to give the attacker an overwhelming advantage to access the secret. In case of ideal schemes, a coalition of a fe...

In Shamir’s ( ) t n , threshold of the secret sharing scheme, a secret s is divided into n shares by a dealer and is shared among n shareholders in such a way that (a) the secret can be reconstructed when there are t or more than t shares; and (b) the secret cannot be obtained when there are fewer than t shares. In the secret reconstruction, participating users can be either legitimate sharehol...

In this chapter we continue our exposition of the crypto topics which was begun in the previous chapter. This chapter covers: Secret Sharing, Threshold Cryptography, Signature Schemes, and nally Quantum Key Distribution and Quantum Cryptography. As in the previous chapter, we have focussed only on the essentials of each topic. We have included in the bibliography suucient items which can be con...

Many efficient secret sharing schemes for general access structures have been developed in efforts to deal with the problems of multi-party computations (MPC), threshold cryptography, and access control. In this paper, we have proposed a novel secret sharing scheme with general access structures that is based on the key-lock-pair mechanism. In our scheme, the dealer can assess a real situation ...

In this paper we study the amount of secret information that must be given to participants in any secret sharing scheme that is secure against coalitions of dishonest participants in the model of Tompa and Woll 20]. We show that any (k; n) threshold secret sharing algorithm in which any coalition of less than k participants has probability of successful cheating less than some > 0 it must give ...

In the paper, we propose three threshold secret sharing schemes that are based on difference equations. The first scheme is a (t, n)− threshold scheme which is an ideal perfect secure. The other two schemes add the restricted order structure to the set of shadows and the access structure of secret sharing policy. The basis of the access structure of one scheme allows that only subsets that cont...

Secret sharing schemes are methods for distributing a secret among n participants in such a way that any qualified subsets of participants can recover the secret, and unqualified participants can not. In 1979, secret sharing schemes were first independently introduced by Blakley and Shamir. In 1987, Feldman proposed a verifiable secret sharing scheme based on Shamir’s Scheme, that every partici...

VSS (verifiable secret sharing) is an important security protection tool in distributed systems. When VSS is employed in publicly verifiable applications, it needs to achieve public verifiability and be upgraded to PVSS (publicly verifiable secret sharing). Besides the two basic security properties, bindingness and hidingness, PVSS concentrates on public verifiability of validity all the operat...