Breaking a quantum key distribution system through a timing side channel
Antı́a Lamas-Linares, Christian Kurtsiefer · Optics Express · 2007
The security of quantum key distribution relies on the validity of quantum mechanics as a description of nature and on the non-existence of leaky degrees of freedom in the practical implementations. We experimentally demonstrate how, in some implementations, timing information revealed during public discussion between the communicating parties can be used by an eavesdropper to undetectably access a significant portion of the "secret" key.