Single-photon watch dog detector for folded quantum key distribution system
US7227955B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 25, 2003 |
| Grant date | Jun 5, 2007 |
| Priority date | — |
| Expiry date | Sep 16, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L9/0858
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A single-photon “watch dog” detector for a two-way quantum key distribution (QKD) system. The detector can detect weak probe signals associated with a Trojan horse attack, or weak substitute signals associated with a “man in the middle” attacks. The detector provides for a significant increase in security for a two-way QKD system over the prior art that employs a conventional detector such as a photodiode. By counting the number of weak pulses entering and/or leaving the reflecting QKD station (Alice), an eavesdropper that attempts to add weak pulses to the quantum channel in order to gain phase information from the phase modulator at Alice can be detected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.