Using Quantum Oblivious Transfer to Cheat Sensitive Quantum Bit Commitment

It is well known that unconditionally secure bit commitment is impossible even in the quantum world. In this paper a weak variant of quantum bit commitment, introduced independently by Aharonov et al. [2] and Hardy and Kent [8] is investigated. In this variant, the parties require some nonzero probability of detecting a cheating, i.e. if Bob, who commits a bit b to Alice, changes his mind during the revealing phase then Alice detects the cheating with a positive probability (we call this property binding); and if Alice gains information about the committed bit before the revealing phase then Bob discovers this with positive probability (sealing). In our paper we give quantum bit commitment scheme that is simultaneously binding and sealing and we show that if a cheating gives advantage to a malicious Alice then Bob can detect the cheating with a probability (2 ). If Bob cheats then Alice's probability of detecting the cheating is greater than some xed constant > 0. This improv...

• Type: Conference
• Year: 2006
• Where: DAGSTUHL
• Authors: Andreas Jakoby, Maciej Liskiewicz, Aleksander Madry
• Keywords: Bit Commitment, Bit Commitment Scheme, DAGSTUHL 2006, DAGSTUHL 2007, Quantum Bit Commitment