Game-Theoretic Security for Bit Commitment

Higo, Tanaka, Yamada, and Yasunaga (ACISP 2012) studied oblivious transfer (OT) from a game-theoretic viewpoint in the malicious model. Their work can be considered as an extension of the study on two-party computation in the fail-stop model by Asharov, Canetti, and Hazay (EUROCRYPT 2011). This paper focuses on bit commitment, and continues to study it from a perspective of game theory. In a similar manner to the work on OT, we consider bit commitment in the malicious model. In order to naturally capture the security properties of bit commitment, we characterize them with a single game where both parties are rational. In particular, we define a security notion from a game theoretic viewpoint, and prove the equivalence between it and the standard security notion.