Quantum cryptography with finite resources: unconditional security bound for discrete-variable protocols with one-way post-processing
Quantum Physics
2009-11-13 v2
Abstract
We derive a bound for the security of QKD with finite resources under one-way post-processing, based on a definition of security that is composable and has an operational meaning. While our proof relies on the assumption of collective attacks, unconditional security follows immediately for standard protocols like Bennett-Brassard 1984 and six-states. For single-qubit implementations of such protocols, we find that the secret key rate becomes positive when at least N\sim 10^5 signals are exchanged and processed. For any other discrete-variable protocol, unconditional security can be obtained using the exponential de Finetti theorem, but the additional overhead leads to very pessimistic estimates.
Cite
@article{arxiv.0708.0709,
title = {Quantum cryptography with finite resources: unconditional security bound for discrete-variable protocols with one-way post-processing},
author = {Valerio Scarani and Renato Renner},
journal= {arXiv preprint arXiv:0708.0709},
year = {2009}
}