Possibility, Impossibility and Cheat-Sensitivity of Quantum Bit String Commitment

Unconditionally secure non-relativistic bit commitment is known to be impossible in both the classical and the quantum worlds. But when committing to a string of n bits at once, how far can they stretch the quantum limits? In this paper, the authors introduce a framework for quantum schemes where Alice commits a string of n bits to Bob in such a way that she can only cheat on a bits and Bob can learn at most b bits of information before the reveal phase.