Adaptive Hardness and Composable Security in the Plain Model from Standard Assumptions

13 years 2 months ago

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We construct the first general secure computation protocols that require no trusted infrastructure other than authenticated communication, and that satisfy a meaningful notion of security that is preserved under universal composition-assuming only the existence of enhanced trapdoor permutations. The notion of security fits within a generalization of the "angelbased" framework of Prabhakaran and Sahai (STOC'04) and implies super-polynomial time simulation security. Security notions of this kind are currently known to be realizable only under strong and specific hardness assumptions. A key element in our construction is a commitment scheme that satisfies a new and strong notion of security. The notion, security against chosen-commitment-attacks (CCA security), means that security holds even if the attacker has access to a extraction oracle that gives the adversary decommitment information to commitments of the adversary's choice. This notion is stronger than concurren...

Ran Canetti, Huijia Lin, Rafael Pass

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