An important parameter in a secret sharing scheme is the number of minimal qualified sets. Given this number, the universal access structure is the richest possible structure, namely the one in which there are one or more participants in every possible Boolean combination of the minimal qualified sets. Every access structure is a substructure of the universal structure for the same number of mi...

This paper describes efficient protocols for multi-party computations that are information-theoretically secure against passive attacks. The results presented here apply to access structures based on quorum systems, which are collections of sets enjoying a naturallymotivated self-intersection property. Quorum-based access structures include threshold systems but are far richer and more general,...

This paper is a survey of the main results and open problems in a line of work that was initiated shortly after secret sharing was introduced. Namely, the construction of ideal linear secret sharing schemes for access structures that are natural generalizations of the threshold ones and have interesting properties for the applications. Some of them have hierarchical properties, while other ones...

An extended visual cryptography scheme, EVCS for short, for an access structure (? Qual ; ? Forb) on a set of n participants, is a technique to encode n images in such a way that when we stack together the transparencies associated to participants in any set X 2 ? Qual we get the secret message with no trace of the original images, but any X 2 ? Forb has no information on the shared image. More...

We carried out a comparative analysis of the algorithms for detecting a rectangular impulse against Gaussian white noise under either authorized or unauthorized access to the transmitted data. We presupposed that for data transmission the binary communication system is used and that the useful information in the data is whether the signal is present or absent. The case is that unauthorized acce...

In SCN2010, Gagné, Narayan, and Safavi-Naini proposed attribute-based signcryption (ABSC) with threshold structure. As in ciphertext-policy attribute-based encryption (CP-ABE), an encryptor can specify the access structure of decryptors, and as in attribute-based signature (ABS), each decryptor can verify the encryptor’s attributes. In contrast to the access structure of decryptors, the access ...