Loss-tolerant quantum secure positioning with weak laser sources

Charles Ci Wen Lim, Feihu Xu, George Siopsis, Eric Chitambar, Philip G. Evans, Bing Qi

Research output: Contribution to journalArticlepeer-review


Quantum position verification (QPV) is the art of verifying the geographical location of an untrusted party. Recently, it has been shown that the widely studied Bennett & Brassard 1984 (BB84) QPV protocol is insecure after the 3 dB loss point assuming local operations and classical communication (LOCC) adversaries. Here, we propose a time-reversed entanglement swapping QPV protocol (based on measurement-device-independent quantum cryptography) that is highly robust against quantum channel loss. First, assuming ideal qubit sources, we show that the protocol is secure against LOCC adversaries for any quantum channel loss, thereby overcoming the 3 dB loss limit. Then, we analyze the security of the protocol in a more practical setting involving weak laser sources and linear optics. In this setting, we find that the security only degrades by an additive constant and the protocol is able to verify positions up to 47 dB channel loss.

Original languageEnglish (US)
Article number032315
JournalPhysical Review A
Issue number3
StatePublished - Sep 14 2016
Externally publishedYes

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics


Dive into the research topics of 'Loss-tolerant quantum secure positioning with weak laser sources'. Together they form a unique fingerprint.

Cite this