Adaptive Zero-Knowledge Proofs and Adaptively Secure Oblivious Transfer

In the setting of secure computation, a set of parties wish to securely compute some function of their inputs, in the presence of an adversary. The adversary in question may be static (meaning that it controls a predetermined subset of the parties) or adaptive (meaning that it can choose to corrupt parties during the protocol execution and based on what it sees). In this paper, we study two fundamental questions relating to the basic zero-knowledge and oblivious transfer protocol problems: ? Adaptive zero-knowledge proofs: We ask whether it is possible to construct adaptive zeroknowledge proofs (with unconditional soundness). Beaver (STOC 1996) showed that known zero-knowledge proofs are not adaptively secure, and in addition showed how to construct zero-knowledge arguments (with computational soundness). ? Adaptively secure oblivious transfer: All known protocols for adaptively secure oblivious transfer rely on seemingly stronger hardness assumptions than for the case of static adver...

• Type: Conference
• Year: 2009
• Where: TCC
• Authors: Yehuda Lindell, Hila Zarosim
• Keywords: Adaptive Zero-knowledge Proofs, Adaptive Zero-knowledge Protocols, Cryptography, Secure Oblivious Transfer, TCC 2009