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The relation between list decoding and hard-core predicates has provided a clean and easy methodology to prove the hardness of certain predicates. So far this methodology has only been used to prove that the O(log log N) least and most significant bits of any function with multiplicative access —which include the most common number theoretic trapdoor(More)
An attribute-based signature with respect to a signing policy , chosen ad-hoc by the signer, convinces the verifier that the signer holds a subset of attributes satisfying that signing policy. Ideally, the ver-ifier must obtain no other information about the identity of the signer or the attributes he holds. This primitive has many applications in real(More)
This paper deals with the design of multi-(micro)computer interconnection networks modelled by graphs. In particular we concentrate upon the optimization of a new family of such networks that turn out to be a generalization of the well-known Arden and Lee's chordal ring networks. This optimization problem leads to the search for certain 3-regular graphs(More)
We put forward a new family of computational assumptions, the Kernel Matrix Diffie-Hellman Assumption. Given some matrix A sampled from some distribution D ,k , the kernel assumption says that it is hard to find " in the exponent " a nonzero vector in the kernel of A. This family is the natural computational analogue of the Matrix Decisional Diffie-Hellman(More)
At Crypto'99, Fujisaki and Okamoto [8] presented a nice generic transformation from weak asymmetric and symmetric schemes into an IND-CCA hybrid encryption scheme in the Random Oracle Model. Two specific candidates for standardization were designed from this transformation: PSEC-2 [14] and EPOC-2 [7], based on El Gamal and Okamoto-Uchiyama primitives,(More)
In a threshold broadcast encryption scheme, a sender chooses (ad-hoc) a set of n receivers and a threshold t, and then encrypts a message by using the public keys of all the receivers, in such a way that the original plaintext can be recovered only if at least t receivers cooperate. Previously proposed threshold broadcast encryption schemes have ciphertexts(More)