Unconditionally Secure Bit Commitment with Flying Qudits
Abstract
In the task cryptographers call bit commitment, one party encrypts a prediction in a way that cannot be decrypted until they supply a key, but has only one valid key. Bit commitment has many applications, and has been much studied, but completely and provably secure schemes have remained elusive. Here we report a new development in physics-based cryptography which gives a completely new way of implementing bit commitment that is perfectly secure. The technique involves sending a quantum state (for instance one or more photons) at light speed in one of two or more directions, either along a secure channel or by quantum teleportation. Its security proof relies on the no-cloning theorem of quantum theory and the no superluminal signalling principle of special relativity.
Cite
@article{arxiv.1101.4620,
title = {Unconditionally Secure Bit Commitment with Flying Qudits},
author = {Adrian Kent},
journal= {arXiv preprint arXiv:1101.4620},
year = {2015}
}
Comments
To appear in New J. Phys. Edits in response to referee comments. Protocol unaltered. Security proofs unaltered but expanded for clarity. Added discussion of strategies for countering errors and losses. Discussions of practicality expanded and qualified, leaving open challenges for experimental implementations