Abstract
The importance of designing a secure quantum bit commitment (QBC) can be seen from its potential applications: remote coin tossing, zero-knowledge proofs, and secure two-party computation. Unconditionally secure QBC has been shown to be impossible (Mayers, 1996). This means that for any QBC protocol to date, there exist cheating that reveal more information than simple guessing. Nevertheless, the effort to break a QBC protocol may be impractical. The present paper explores the cheating strategy for a QBC designed within two equivalence classes and evaluates the complexity of a cheating attack and its practicality.