The Simplest Protocol for Oblivious Transfer [chapter]

Tung Chou, Claudio Orlandi
2015 Lecture Notes in Computer Science  
Oblivious Transfer (OT) is one of the fundamental building blocks of cryptographic protocols. In this paper we describe the simplest and most efficient protocol for 1-out-of-n OT to date, which is obtained by tweaking the Diffie-Hellman key-exchange protocol. The protocol allows to perform m 1-out-of-n OTs using only 2 + 3m full exponentiations (2m for the receiver, 2 + m for the sender) and, sending only m + 1 group elements and 2mn ciphertexts. We also report on an implementation of the
more » ... ol using elliptic curves, and on a number of mechanisms we employ to ensure that our software is secure against active attacks too. Experimental results show that our protocol (thanks to both algorithmic and implementation optimizations) is at least one order of magnitude faster than previous work. Update: The proceeding version of this paper contains incorrect claims. See Section 1.1 for details.
doi:10.1007/978-3-319-22174-8_3 fatcat:wqaiqviqfbctbfxp46ptolsjra