Description
We introduce a new computational problem related to the interpolation of group homomorphisms which generalizes many famous cryptographic problems including discrete logarithm, Diffie-Hellman, and RSA. As an application, we propose a generic undeniable signature scheme which generalizes the MOVA schemes. Our scheme is generic in the sense that we transform a private group homomorphism from public groups G to H (the order of H being public) into an undeniable signature scheme. It is provably secure in the random oracle model provided that the interpolation problem is hard and it offers the advantage of making the signature size arbitrarily short (depending on a security level). We (im)prove some security results from MOVA. We also propose a new example with complexity similar to RSA and with 3-byte signatures.
Prochains exposés
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CryptoVerif: a computationally-sound security protocol verifier
Orateur : Bruno Blanchet - Inria
CryptoVerif is a security protocol verifier sound in the computational model of cryptography. It produces proofs by sequences of games, like those done manually by cryptographers. It has an automatic proof strategy and can also be guided by the user. It provides a generic method for specifying security assumptions on many cryptographic primitives, and can prove secrecy, authentication, and[…]-
Cryptography
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