Robust t-out-of-n oblivious transfer mechanism based on CRT

Providing private communications for involved participants, the oblivious transfer (OT) mechanism is an important component in many cryptography applications such as e-commerce, secret exchange, coin flipping by telephone and sending certified e-mail. Recently, Mu et al. extended the OT concept to a t-out-of-n version (denoted as OTtn). They claim that the novel method allows the chooser to simultaneously obtain t messages from the sender in each protocol run. Wu et al.'s improvements make an OT mechanism more flexible and efficient. Unfortunately, we propose a strategy to demonstrate that their method is unable to provide the privacy of the sender in this article. Furthermore, we present a novel OTtn mechanism based on the concepts of blind signature and the Chinese remainder theorem. This novel mechanism achieves the essentials of general OT mechanisms. (C) 2008 Elsevier Ltd. All rights reserved.