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.

A perfect threshold secret sharing scheme to identify cheaters

Abstract: In this paper we consider the problem of identifying cheaters in secret sharing schemes. Rabin and Ben-Or presented a perfect and unconditionally secure secret sharing scheme in which the honest participants are able to identify the cheaters. We present a similar scheme, but one in which the information distributed to each participant is smaller.

Blockchain-Based Personal Health Records Sharing Scheme With Data Integrity Verifiable

Abstract: The sharing of personal health records can help to improve the accuracy of the doctor's diagnosis and to promote the progress of medical research. Currently, to reduce the maintenance cost of data, personal health records are usually outsourced to a third party such as the cloud service provider. In this case, patients may lose direct control over their personal health records and the semi-trusted cloud service provider may tamper with or reveal personal health records. Therefore, ensuring the privacy and integrity of personal health records and realizing the fine-grained access control are crucial issues when personal health records are shared. As a distributed architecture with decentralized and tamper-proof features, blockchain provides a new way to protect the personal health records sharing system. In this paper, we propose a new personal health records sharing scheme with data integrity verifiable based on blockchain. Aiming at the problems of privacy disclosure, limited keyword search ability and loss of control rights in the process of personal health record sharing, the new scheme uses searchable symmetric encryption and attribute-based encryption techniques to achieve privacy protection, keyword search, and fine-grained access control. Compared with the existing similar schemes, the new scheme allows patients to distribute attribute private key for users, avoiding many security problems caused by the existing of attribute authority in the scheme. Furthermore, the new scheme uses blockchain to manage keys in the scheme, avoiding the single point failure problem of centralized key management. In particular, the new scheme stores the hash values of encrypted personal health records in blockchain, and the related index set is stored in smart contract, which can further improve the efficiency of data integrity verification. Finally, performance evaluation and security analysis indicate that our scheme is secure and feasible for practical use.

Method and system for providing translation certificates

Abstract: A method for providing publicly verifiable translation certificates comprising the steps of receiving an input encryption having a first secret key; outputting an output re-encryption of the input encryption, the output re-encryption having a second secret key; and generating a translation certificate that proves the input encryption and the output re-encryption are encryptions of an identical message, wherein the first secret key and the second secret key do not need to be, but are allowed to be, equal. This method and system for generating translation certificates in quorum controlled asymmetric proxy encryptions has uses, including but not limited to, Internet applications and specifically to E-mail systems. The scheme, which can use either an ElGamal encryption, an ElGamal encryption based on Elliptic Curves or an ElGamal related encryption algorithm, leaks no information as long as there is no dishonest quorum of proxy servers and produces a small, publicly verifiable translation certificate, that is independent of the number of prover servers involved in the re-encryption.

Improving the Round Complexity of VSS in Point-to-Point Networks

Abstract: We revisit the following question: what is the optimal round complexity of verifiable secret sharing (VSS)? We focus here on the case of perfectly-secure VSS where the number of corrupted parties tsatisfies t< n/3, with nbeing the total number of parties. Work of Gennaro et al. (STOC 2001) and Fitzi et al. (TCC 2006) shows that, assuming a broadcast channel, 3 rounds are necessary and sufficient for efficient VSS. The efficient 3-round protocol of Fitzi et al., however, treats the broadcast channel as being available "for free" and does not attempt to minimize its usage. This approach leads to relatively poor round complexity when protocols are compiled for a point-to-point network. We show here a VSS protocol that is simultaneouslyoptimal in terms of both the number of rounds and the number of invocations of broadcast. Our protocol also has a certain "2-level sharing" property that makes it useful for constructing protocols for general secure computation.