Publicly Verifiable Secret Sharing Scheme Research Articles

Cryptanalysis and improvement of Q. Peng et al.’s PVSS scheme

A publicly verifiable secret sharing (PVSS) scheme based on the m-multilinear Diffie-Hellman hard assumption was proposed by Q. Peng et al., where the public values published by a dealer are verifiable before reconstructing a secret. In addition, the scheme has the advantages that the shares’ cheating/modification by some dishonest participants and dealer’s malicious behavior in shares’ generation and/or distribution can be detected. In this work, we cryptanalyze the scheme and find that a well-known attack called man-in-the-middle (MITM) is possible if the users’ secret shares are modified because they remain undetected and, as a result, a modified common secret is reconstructed by a group of any 1 < t ≤ n participants. We address this issue and propose some modifications of the PVSS scheme with ( m + 1 ) multilinear operations and two additional public values such that the MITM attack is infeasible and the scheme becomes secure. In addition, the proposed improvement is made adeptly without hampering performance, i.e., the computation cost has been marginally increased in our proposed improvement.

A Publicly Verifiable Multi-Secret Sharing Scheme With Outsourcing Secret Reconstruction

A publicly verifiable secret sharing (PVSS) scheme enjoys the public verification and the lower cost of communication than VSS scheme. However, the existing PVSS schemes cannot be applied in the scenarios of the devices with low computation ability and do not share the multiple secrets among all participants efficiently. In this paper, an efficient publicly verifiable multi-secret sharing scheme with outsourcing secret reconstruction is proposed. Each participant only spends a small amount of computational cost to recover multiple secrets because of the expensive burden of computation and verifiability is outsourced to the cloud service provider (CSP). Moreover, the CSP knows no information of the secrets, and the participants have the abilities to verify the returned result. We also prove that our scheme is secure under the hardness assumption of the discrete logarithm problem and the modified generalized bilinear inversion problem.

A New PVSS Scheme with a Simple Encryption Function

A Publicly Verifiable Secret Sharing (PVSS) scheme allows anyone to verify the validity of the shares computed and distributed by a dealer. The idea of PVSS was introduced by Stadler in [18] where he presented a PVSS scheme based on Discrete Logarithm. Later, several PVSS schemes were proposed. In [2], Behnad and Eghlidos present an interesting PVSS scheme with explicit membership and disputation processes. In this paper, we present a new PVSS having the advantage of being simpler while offering the same features.

A pairing-based publicly verifiable secret sharing scheme

A publicly verifiable secret sharing (PVSS) scheme is a verifiable secret sharing scheme with the special property that anyone is able to verify the shares whether they are correctly distributed by a dealer. PVSS plays an important role in many applications such as electronic voting, payment systems with revocable anonymity, and key escrow. Up to now, all PVSS schemes are based on the traditional public-key systems. Recently, the pairing-based cryptography has received much attention from cryptographic researchers. Many pairing-based schemes and protocols have been proposed. However, no PVSS scheme using bilinear pairings is proposed. This paper presents the first pairing-based PVSS scheme. In the random oracle model and under the bilinear Diffie-Hellman assumption, the authors prove that the proposed scheme is a secure PVSS scheme.

Publicly Verifiable Secret Sharing Member-join Protocol For Threshold Signatures

Publicly verifiable secret sharing (PVSS) allows not only shareholders themselves but also everyone verify the shares of a secret distributed by a dealer. It has a lot of electronic applications. In this paper, we propose a publicly verifiable member-join protocol for threshold signatures. In our proposal, a new member can join a PVSS scheme to share the secret only with the help of old shareholders. What’s more, everyone besides the new member can verify the validity of the new member’s share, while only the new member knows his share. Different from previous protocols, our protocol can tolerate a mobile adversary. This proposal adapts to many electronic applications. Finally, we analyze the security of our scheme.