Extending white-box cryptography based oblivious transfer protocol

Secure computation platforms are becoming one of the most demanded cryptographic tools utilized in diverse applications, where the performance is critical. This point makes important the optimization of every component of secure computation systems. Oblivious Transfer (OT) is a fundamental cryptographic primitive heavily used in such protocols. Most of the OT protocols used today are based on public-key cryptography, hence their efficiency suffers heavily from the number of modular exponentiation operations done. OT extensions were introduced to reduce the number of basic OT protocol execution rounds requiring public-key cryptography operations. Recently a white-box cryptography based OT protocol (WBOT) was introduced that avoids using expensive public-key operations. In this article extension protocols for WBOT are presented, that further improve the novel approach by dramatically decreasing the protocol invocation count required.