Arbitrarily long relativistic bit commitment
Abstract
We consider the recent relativistic bit commitment protocol introduced by Lunghi et al. [Phys. Rev. Lett. 2015] and present a new security analysis against classical attacks. In particular, while the initial complexity of the protocol scaled double-exponentially with the commitment time, our analysis shows that the correct dependence is only linear. This has dramatic implications in terms of implementation: in particular, the commitment time can easily be made arbitrarily long, by only requiring both parties to communicate classically and perform efficient classical computation.
Cite
@article{arxiv.1507.00239,
title = {Arbitrarily long relativistic bit commitment},
author = {Kaushik Chakraborty and André Chailloux and Anthony Leverrier},
journal= {arXiv preprint arXiv:1507.00239},
year = {2015}
}
Comments
In an independent and concurrent work, Fehr and Fillinger [FF15] proved a general composition theorem for two-prover commitments which implies a similar bound on the security of the Lunghi et al. protocol than the one derived here