Universally Composable Adaptive Priced Oblivious Transfer

  • Alfredo Rial
  • Markulf Kohlweiss
  • Bart Preneel
Conference paper

DOI: 10.1007/978-3-642-03298-1_15

Volume 5671 of the book series Lecture Notes in Computer Science (LNCS)
Cite this paper as:
Rial A., Kohlweiss M., Preneel B. (2009) Universally Composable Adaptive Priced Oblivious Transfer. In: Shacham H., Waters B. (eds) Pairing-Based Cryptography – Pairing 2009. Pairing 2009. Lecture Notes in Computer Science, vol 5671. Springer, Berlin, Heidelberg

Abstract

An adaptive k-out-of-N Priced Oblivious Transfer (POT) scheme is a two-party protocol between a vendor and a buyer. The vendor sells a set of messages m1, . . . ,mN with prices p1, . . . , pN. In each transfer phase i = 1, . . . , k, the buyer chooses a selection value σi ∈ {1, . . . ,N} and interacts with the vendor to buy message mσi in such a way that the vendor does not learn σi and the buyer does not get any information about the other messages.

We present a POT scheme secure under pairing-related assumptions in the standard model. Our scheme is universally composable and thus, unlike previous results, preserves security when it is executed with multiple protocol instances that run concurrently in an adversarially controlled way. Furthermore, after an initialization phase of complexity O(N), each transfer phase is optimal in terms of rounds of communication and it has constant computational and communication cost. To achieve these properties, we design the first efficient non-interactive proof of knowledge that a value lies in a given interval we are aware of.

Keywords

Universally composable security priced oblivious transfer bilinear maps non-interactive range proofs of knowledge 

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Copyright information

© Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  • Alfredo Rial
    • 1
  • Markulf Kohlweiss
    • 1
  • Bart Preneel
    • 1
  1. 1.ESAT/SCD/COSIC and IBBTKatholieke Universiteit LeuvenBelgium