Efficient k-out-of-n Oblivious Transfer Schemes with Adaptive and Non-Adaptive Queries

Cheng-Kang Chu; Wen-Guey Tzeng

Paper 2004/041

Efficient k-out-of-n Oblivious Transfer Schemes with Adaptive and Non-Adaptive Queries

Cheng-Kang Chu and Wen-Guey Tzeng

Abstract

In this paper we propose a very efficient two-round k-out-of-n oblivious transfer scheme, in which R sends O(k) messages to S, and S sends O(n) messages back to R. The computation cost of R and S is reasonable as R needs O(k) operations and S needs O(n)operations. The choices of R are unconditionally secure and the secrecy of unchosen messages is guaranteed as well if the decisional bilinear Diffie-Hellman problem is hard. When k=1, our scheme is as efficient as the most efficient 1-out-of-n oblivious transfer scheme up to now. Our scheme has the nice property of universal parameters. That is, each pair of R and S need neither hold any secret key nor perform any prior setup. The system parameters can be used by all senders and receivers without any trapdoor specification. Our k-out-of-n oblivious transfer scheme is the most efficient one in terms of the communication cost, in both rounds and the number of messages. Moreover, our scheme can be extended in a straightforward way to an adaptive k-out-of-n oblivious transfer scheme, which allows the receiver R to choose the secrets one by one adaptively. In our scheme, S sends O(n) messages to R in one round in the commitment phase. For each query of R, only O(1) messages are exchanged and O(1) operations (in elliptic curves) are performed. In fact, the number k of queries need not be pre-fixed or known beforehand. This makes our scheme highly flexible.

Note: The scheme against semi-honest receivers has been improved.

Metadata

Available format(s): PS
Category: Cryptographic protocols
Publication info: Published elsewhere. PKC 2005
Keywords: Oblivious Transfer
Contact author(s): ckchu @ cis nctu edu tw
History: 2004-11-24: last of 7 revisions; 2004-02-16: received; See all versions
Short URL: https://ia.cr/2004/041
License: CC BY

BibTeX

@misc{cryptoeprint:2004/041,
      author = {Cheng-Kang Chu and Wen-Guey Tzeng},
      title = {Efficient k-out-of-n Oblivious Transfer Schemes with Adaptive and Non-Adaptive Queries},
      howpublished = {Cryptology {ePrint} Archive, Paper 2004/041},
      year = {2004},
      url = {https://eprint.iacr.org/2004/041}
}