In order to decide on advertisement fees for web servers, Naor and Pinkas introduced (threshold) metering schemes secure against coalitions of corrupt servers and clients. Several researchers have generalized the idea of Naor and Pinkas: first metering scheme with pricing and dynamic multi-threshold metering schemes have been proposed; later the solution has been extended to allow general acces...

Recently Hirt and Maurer [3] introduced the notion of Q(Q) adversary structure. In this paper we generalize this notion by defining new operation on access structures and we describe some applications of the new definition. There is one-to-one correspondence between access structures and monotone Boolean functions, defined on bipartite graphs.

0167-8655/$ see front matter 2012 Published by http://dx.doi.org/10.1016/j.patrec.2012.04.010 ⇑ Corresponding author. Address: Department of Computer Science, Feng Chia University, No. 100 We 40724, Taiwan. Tel.: +886 4 24517250x3790; fax: +8 E-mail addresses: [email protected] (C. Guo Chang). In this paper, we consider the problem of secret image sharing in groups with multi-threshold access s...

If an image can be converted into a point in plane or space, lots of image problems can be considered based on geometric and vector theory. In this paper, the “image to point” conversion via complex number basis is proposed. Combined with the existing threshold access structures scheme, it leads to proposal of using number based secret sharing schemes in color images sharing.

Secret sharing is a cryptographic primitive, which is used to distribute a secret among participants in such a way that an authorized subset of participants can uniquely reconstruct the secret and an unauthorized subset can get no information about the secret. It is a fundamental method used in secure multiparty computations, where various distrusted participants cooperate and conduct computati...

In this paper we extend the threshold secret sharing schemes based on the Chinese remainder theorem in order to deal with more general access structures. Aspects like verifiability, secret sharing homomorphisms and multiplicative properties are also discussed. AMS Subject Classification: 94A62, 11A07

Secret-sharing schemes are an important tool in cryptography that is used in the construction of many secure protocols. However, the shares’ size in the best known secret-sharing schemes realizing general access structures is exponential in the number of parties in the access structure, making them impractical. On the other hand, the best lower bound known for sharing of an `-bit secret with re...