Implementing Oblivious Transfer Using Collection of Dense Trapdoor Permutations

Abstract. Until recently, the existence of collection of trapdoor permutations (TDP) was believed (and claimed) to imply almost all of the major cryptographic primitives, including public-key encryption (PKE), oblivious transfer (OT), and non-interactive zero-knowledge (NIZK). It was recently realized, however, that the commonly accepted general definition of TDP needs to be strengthened slightly in order to make the security proofs of TDP-based OT go through. We present an implementation of oblivious transfer based on collection of dense trapdoor permutations. The latter is a collection of trapdoor permutations, with the property that the permutation domains are polynomially dense in the set of all strings of a particular length. Previous TDP-based implementations of oblivious transfer assumed an enhancement of the hardness assumption (of the collection).

• Type: Conference
• Year: 2004
• Where: TCC
• Authors: Iftach Haitner
• Keywords: Cryptography, Dense Trapdoor Permutations, Oblivious Transfer, TCC 2004, Trapdoor Permutations