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 ). 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 mechanism based on the concepts of blind signature and the Chinese remainder theorem. This novel mechanism achieves the essentials of general OT mechanisms.
Journal of Network and Computer Applications 32(1):226-235