We present a new protocol for verifiably redistributing secrets from an (m,n) threshold sharing scheme to an (m′, n′) scheme. Our protocol guards against dynamic adversaries. We observe that existing protocols either cannot be readily extended to allow redistribution between different threshold schemes, or have vulnerabilities that allow faulty old shareholders to distribute invalid shares to n...

In this paper we propose a simple PVSS scheme based on the homomorphic properties of Paillier’s encryption scheme. This new scheme is the first known PVSS scheme based on the decisional composite residuosity assumption. The verification process in this scheme is much simpler than in the other known schemes. Furthermore, in our proposal, verification is made non-interactive without using the Fia...

In this work we focus on two basic secure distributed computation tasksProbabilistic Weak Secret Sharing (PWSS) and Probabilistic Verifiable Secret Sharing (PVSS). PVSS allows a dealer to share a secret among several players in a way that would later allow a unique reconstruction of the secret with negligible error probability. PWSS is slightly weaker version of PVSS where the dealer can choose...

C.-C. Yang, T.-Y. Chang, M.-S. Hwang [C.-C. Yang, T.-Y. Chang, M.-S. Hwang, A (t,n) multi-secret sharing scheme, Applied Mathematics and Computation 151 (2004) 483–490] proposed an efficient multi-secret sharing scheme based on a two-variable one-way function in 2004. But the scheme doesn't have the property of verification. A practical verifiable multi-secret sharing scheme, which is based on ...

In 1979, secret sharing schemes were first proposed by Blakley and Shamir. In a secret sharing scheme, each participant receives a share of a secret in such a way that only authorized subsets can reconstruct the secret. Later, Wu and He proposed a (t, n)-threshold scheme for sharing a secret based on a hyperspherical function (HS-TS). Their scheme give a practical algorithm to solve the problem...

Farnel is a voting scheme which first introduced the concept of a ballot box to exchange votes. Recently, Araújo et al. improved this concept to accomplish a voter-verifiable scheme in which voters receive copies of receipts of one or more randomly selected previous cast votes. The scheme, however, relies on a strong requisite to achieve security: trustworthy talliers. With the goal of removing...

Verifiable random functions are pseudorandom functions producing publicly verifiable proofs for their outputs, allowing for efficient checks of the correctness of their computation. In this work, we introduce a new computational hypothesis, the n-Eigen-Value assumption, which can be seen as a relaxation of the Un MDDH assumption, and prove its equivalence with the n-Rank assumption. Based on th...

Franklin and Reiter introduced at Eurocrypt '95 verifiable signature sharing, a primitive for a fault tolerant distribution of signature verification. They proposed various praclical protocols. For RSA signatures with exponent e = 3 and n processors their protocol allows for up to (n 1)/5 faulty processors (in general (n 1)/(2 + e)). We consider a new unifying approach which uses homomorphisms ...