In many pairing-based cryptosystems, the secret keys are elements of bilinear groups. For safeguarding such secret keys or decrypting or signing in a threshold manner, Verifiable Secret Sharing (VSS) in bilinear groups is required. In this paper, we show a method of verifiably sharing a random secret in a bilinear group. Our method is simple and practical. It can be regarded as a generalisation...

The information ratio of a secret sharing scheme Σ measures the size of the largest share of the scheme, and is denoted by σ(Σ). The optimal information ratio of an access structure Γ is the infimum of σ(Σ) among all schemes Σ for Γ, and is denoted by σ(Γ). The main result of this work is that for every two access structures Γ and Γ′, |σ(Γ)− σ(Γ′)| ≤ |Γ∪ Γ′| − |Γ∩ Γ′|. We prove it constructivel...

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...

This paper presents a copyright protection scheme based on discrete cosine transform (DCT) and secret sharing techniques. The proposed scheme first utilizes the features of a host image, obtained by performing the DCT on the host image, to generate a master share. Then, the master share is used together with a binary watermark to create an ownership share by employing the secret sharing techniq...

We construct a perfect extrinsic secret sharing scheme for any case in which a set of participants can gain access to the secret if and only if the set contains a pair of members from some given list of pairs. A secret sharing scheme is a way by which a dealer rnay distribute secret information to individuals (call participants). There is associated '-<U.lh'.lcH"""F-of subsets of a set of can i...

We propose a unitary procedure to reconstruct quantum secret for a quantum secret sharing scheme constructed from stabilizer quantum errorcorrecting codes. Erasure correcting procedures for stabilizer codes need to add missing shares for reconstruction of quantum secret while unitary reconstruction procedures for certain class of quantum secret sharing are known to work without adding missing s...

Visual cryptography (VC) has been developed extensively based on its practicability. These schemes can encode a black-and-white secret image into several shadow images, and, by stacking a certain number of shadow images, can retrieve the secret image through the human visual system. In this paper, we employ Hsu et al.’s ideal multi-threshold secret sharing scheme based on monotone span programs...

Recently, verifiable secret sharing schemes have been proposed to keep participants from providing fake or illegal stego-images. However, the schemes do not consider the recovery mechanism when parts of the information in stego-images are lost or incidentally modified during the transmission process. This paper presents a novel verifiable and reversible secret sharing scheme based on Shamir’s s...

Lee and Hwang proposed a multi-stage (t, n) secret sharing scheme which has fewer public values than pervious schemes. In their scheme, a group of participants share multiple secrets stage-by-stage, and only one secret share should been kept by each participant. However, in this article, we will show that multiple secrets cannot, in fact, be reconstructed stage-by-stage by the secret holder’s d...

Considering the case of players’ deceptions, traditional secret sharing scheme can not resolve the security issues. To address these security issues, the paper proposes a rational secret sharing scheme against cheating based on game theory. Under the conditions of the rational, applying the idea of threshold, the scheme is composed of key generation, share encryption, verification and secret re...