Oblivious Transfer ( \(\textsf{OT}\) ) is a fundamental cryptographic primitive that becomes a crucial component of a practical secure protocol. \(\textsf{OT}\) is typically implemented in software, and one way to accelerate its running time is by using hardware implementations. However, such implementations are vulnerable to side-channel attacks (SCAs). On the other hand, protecting interactive protocols against SCA is highly challenging due to their longer secrets (which include inputs and randomness), more complex design, and the need to run multiple instances. Consequently, there are no truly practical leakage-resistant \(\textsf{OT}\) protocols yet. In this paper, we introduce two tailored indistinguishability-based security definitions for leakage-resilient \(\textsf{OT}\) , focusing on protecting the sender’s state. Second, we propose a practical semi-honest secure \(\textsf{OT}\) protocol that achieves these security levels while minimizing the assumptions on the protocol’s building blocks and the use of a secret state.
