Robuster Combiners for Oblivious Transfer

Abstract. A (k; n)-robust combiner for a primitive F takes as input n candidate implementations of F and constructs an implementation of F, which is secure assuming that at least k of the input candidates are secure. Such constructions provide robustness against insecure implementations and wrong assumptions underlying the candidate schemes. In a recent work Harnik et al. (Eurocrypt 2005) have proposed a (2; 3)-robust combiner for oblivious transfer (OT), and have shown that (1; 2)-robust OT-combiners of a certain type are impossible. In this paper we propose new, generalized notions of combiners for two-party primitives, which capture the fact that in many two-party protocols the security of one of the parties is unconditional, or is based on an assumption independent of the assumption underlying the security of the other party. This fine-grained approach results in OT-combiners strictly stronger than the constructions known before. In particular, we propose an OT-combiner which guar...

• Type: Conference
• Year: 2007
• Where: TCC
• Authors: Remo Meier, Bartosz Przydatek, Jürg Wullschleger
• Keywords: Combiner, Constructions Provide Robustness, Cryptography, N)-robust Combiner, TCC 2007