In this paper, a new broadcast encryption scheme is presented based on threshold secret sharing and secure multiparty computation. This scheme is maintained to be dynamic in that a broadcaster can broadcast a message to any of the dynamic groups of users in the system and it is also fair in the sense that no cheater is able to gain an unfair advantage over other users. Another important feature...

In this paper, we investigate a new concept, called share selectable secret sharing, where no unauthorized set can obtain information of the secret (in the information-theoretic sense) even if shares are selectable as arbitrary values which are independent of the secret. We propose two totally selectable (i.e., all users’ shares are selectable) secret sharing schemes with unanimous structure. W...

This paper describes an efficient (k, n) threshold digital signature scheme. In the scheme, k out of n signers cooperate to issue a signature without using trusted center. No secret communication is required among signers across the network. As a base scheme, Pedersen's verifiable secret sharing (VSS) is applied to generate shared secret keys in such a way that no secret communication is requir...

Password-protected secret sharing (PPSS) schemes allow a user to publicly share its high-entropy secret across different servers and to later recover it by interacting with some of these servers using only his password without requiring any authenticated data. In particular, this secret will remain safe as long as not too many servers get corrupted. However, servers are not always reliable and ...

Visual Cryptography Scheme (VCS) is an encryption method that works on human visual system. It encrypts a secret image into n shares and decryption can be done only by stacking k or more share images without any computation. A new secret sharing scheme with meaningful shares using (k,n)-threshold visual cryptography and digital watermarking for grayscale images based on bit plane encoding is pr...

This study presents an expandable essential secret image sharing structure showing that some important shared images, named essential ones, are necessary when recovering the secret image and the proposed structure must incorporate other secret image sharing scheme to expand to a new secret image sharing scheme with multiple functions. An (s, t, n) essential secret image sharing structure shares...

A black-box secret sharing scheme for the threshold access structure Tt,n is one which works over any finite Abelian group G. Briefly, such a scheme differs from an ordinary linear secret sharing scheme (over, say, a given finite field) in that distribution matrix and reconstruction vectors are defined over Z and are designed independently of the group G from which the secret and the shares are...

In this study, a new (r, n)-threshold secret image sharing scheme with low information overhead for images is provided, which has a low distortion rate, and is more applicable for light images. A secret image is encoded into n noise-like shadow images to satisfy the condition that any r of the n shares can be used to reveal the secret image, and no information on the secret can be revealed from...

This paper proposes a special type secret image sharing method. Based on the theories of secret image sharing and frequency domain transform, a multi-threshold secret image sharing is achieved. The method contains more properties compared with conventional secret image sharing which just has only one threshold. The properties of the proposed method include fault tolerance, small size of shares,...

In this paper, we show an eecient (k; n) threshold secret sharing scheme over any nite Abelian group such that the size of share is q=2 (where q is a prime satisfying n q < 2n), which is a half of that of Desmedt and Frankel's scheme. Consequently, we can obtain a threshold RSA signature scheme in which the size of shares of each signer is only a half.