Verifiable secret sharing

About: Verifiable secret sharing is a research topic. Over the lifetime, 4241 publications have been published within this topic receiving 99569 citations.

Zaps and Their Applications

Abstract: A zap is a 2-round, public coin witness-indistinguishable protocol in which the first round, consisting of a message from the verifier to the prover, can be fixed “once and for all” and applied to any instance. We present a zap for every language in NP, based on the existence of noninteractive zero-knowledge proofs in the shared random string model. The zap is in the standard model and hence requires no common guaranteed random string. We present several applications for zaps, including 3-round concurrent zero-knowledge and 2-round concurrent deniable authentication, in the timing model of Dwork, Naor, and Sahai [J. ACM, 51 (2004), pp. 851-898], using moderately hard functions. We also characterize the existence of zaps in terms of a primitive called verifiable pseudorandom bit generators.

New efficient and secure protocols for verifiable signature sharing and other applications

Abstract: Verifiable Signature Sharing (VΣS) enables the recipient of a digital signature, who is not necessarily the original signer, to share such signature among n proxies so that a subset of them can later reconstruct it. The original RSA and Rabin VΣS protocols were subsequently broken and the original DSS VΣS lacks a formal proof of security. We present new protocols for RSA, Rabin and DSS VΣS. Our protocols are efficient and provably secure and can tolerate the malicious behavior of up to half of the proxies. Furthermore we believe that some of our techniques are of independent interest. Some of the by-products of our main result are: a new threshold cryptosystem, a new undeniable signature scheme and a way to create binding RSA cryptosystems.

A Secure End-to-End Verifiable Internet-Voting System Using Identity-Based Blind Signature

Abstract: The end-to-end (E2E) verification enables a voter to check if his ballot is recorded as he intended and the public to check if the system has correctly counted all of the recorded ballots. The Internet voting systems based on the principle of E2E verifiability have many challenges; the most important is its security. Several E2E voting systems have been discussed in the last decade in terms of analyzing the e-voting system and formalizing its security requirements. This article presents an E2E verifiable internet voting system that provides mobility to a voter and allows him to cast his vote secretly in public computer with the benefit of early voting. The proposed system aims to support the election process universally by using the voter's unique identification and biometric features. We propose a new identity-based blind signature scheme that ensures the voter's anonymity. We adopt the Boneh–Lynn–Shacham short signature scheme that ensures the vote privacy with the least ballot size. The system provides a digital witness to a voter that enables him to check whether his vote is recorded as he meant and the public to check if all the recorded ballots are counted correctly. The privacy of the proposed system is achieved under the well-known elliptic curve discrete logarithm and gap Diffie–Hellman assumptions.

Study on Secret Sharing Schemes (SSS) and their applications

Abstract: Hiding a secret is needed in many situations. One might need to hide a password, an encryption key, a secret recipe, and etc. Information can be secured with encryption, but the need to secure the secret key used for such encryption is important too. Imagine you encrypt your important files with one secret key and if such a key is lost then all the important files will be inaccessible. Thus, secure and efficient key management mechanisms are required. One of them is secret sharing scheme (SSS) that lets you split your secret into several parts and distribute them among selected parties. The secret can be recovered once these parties collaborate in some way. This paper will study these schemes and explain the need for them and their security. Across the years, various schemes have been presented. This paper will survey some of them varying from trivial schemes to threshold based ones. Explanations on these schemes constructions are presented. The paper will also look at some applications of SSS.

On the Information Rate of Secret Sharing Schemes (Extended Abstract)

Abstract: We derive new limitations on the information rate and the average information rate of secret sharing schemes for access structure represented by graphs. We give the first proof of the existence of access structures with optimal information rate and optimal average information rate less that 1/2 + ?, where ? is an arbitrary positive constant. We also provide several general lower bounds on information rate and average information rate of graphs. In particular, we show that any graph with n vertices admits a secret sharing scheme with information rate ?((logn)/n).