Lo develops quantum-key-distribution protocols, including decoy-state and measurement-device-independent approaches that address concrete weaknesses in practical optical systems.
University of Toronto Department of PhysicsarXivarXivQuantum cryptography must connect a security proof to imperfect sources and detectors. Lo's coauthored decoy-state work uses vacuum or weak pulses to test the behavior of a communication channel, while measurement-device-independent QKD is designed to remove detector side channels from the security boundary. These are distinct protocol contributions with explicit models, not a claim that any optical link is secure by default.
University of Toronto Department of PhysicsarXivarXivDefining contributions
Work, in context- 2004
Vacuum and weak-pulse decoy states
With Xiongfeng Ma and Kai Chen, Lo proposed using vacuum or very weak coherent pulses as decoy states in quantum key distribution. The method gives communicating parties additional observations for detecting attacks that exploit multi-photon pulses in practical sources.
Joint theoretical work by Hoi-Kwong Lo, Xiongfeng Ma and Kai Chen; the source identifies the 2004 conference publication and the later preprint record.
Source-supported recordarXiv - 2011
Measurement-device-independent quantum key distribution
Lo, Marcos Curty and Bing Qi proposed measurement-device-independent quantum key distribution, an architecture designed so detector side channels do not compromise the key within the protocol's model. The proposal uses standard optical components and moves measurement trust outside the communicating endpoints.
Joint theoretical work by Hoi-Kwong Lo, Marcos Curty and Bing Qi; performance and security claims depend on the assumptions and parameters analyzed in the paper.
Source-supported recordarXiv
Keep in perspective
A protocol-level security result does not certify a particular network. Sources, state preparation, parameter estimation, classical processing and implementation-specific side channels still require assessment.
The evidence map
Person → documented contribution → supporting source. Select a contribution to inspect what the evidence establishes.
Vacuum and weak-pulse decoy states
Quantum Key Distribution with Vacua or Dim Pulses as Decoy States
Supports: Authorship, vacuum and weak-coherent-state decoy proposal, and the source's record of its 2004 conference publication.
Published Sep 11, 2005 · Checked Sep 20, 2026Credit & limits: Joint theoretical work by Hoi-Kwong Lo, Xiongfeng Ma and Kai Chen; the source identifies the 2004 conference publication and the later preprint record.
Read the full contribution| Contribution | Evidence & what it supports | Credit & limits |
|---|---|---|
| Vacuum and weak-pulse decoy states2004 | Primary paperQuantum Key Distribution with Vacua or Dim Pulses as Decoy States Authorship, vacuum and weak-coherent-state decoy proposal, and the source's record of its 2004 conference publication. Published 2005-09-11 · Checked 2026-09-20 | Joint theoretical work by Hoi-Kwong Lo, Xiongfeng Ma and Kai Chen; the source identifies the 2004 conference publication and the later preprint record. |
| Measurement-device-independent quantum key distribution2011 | Primary paperMeasurement-device-independent quantum key distribution Authorship, detector-side-channel motivation, protocol architecture and implementation claims; date is the first preprint submission. Published 2011-09-07 · Checked 2026-09-20 | Joint theoretical work by Hoi-Kwong Lo, Marcos Curty and Bing Qi; performance and security claims depend on the assumptions and parameters analyzed in the paper. |
Follow the evidence
3 sourcesPrimary papers, institutional records and attributed announcements. Each source supports the claims linked above.
- University of Toronto Department of PhysicsInstitutional record
Hoi-Kwong Lo
Current cross-appointment in the Department of Physics and membership in the Quantum Optics group.
Checked 2026-09-20 - arXivPrimary paper
Quantum Key Distribution with Vacua or Dim Pulses as Decoy States
Authorship, vacuum and weak-coherent-state decoy proposal, and the source's record of its 2004 conference publication.
Published 2005-09-11 · Checked 2026-09-20 - arXivPrimary paper
Measurement-device-independent quantum key distribution
Authorship, detector-side-channel motivation, protocol architecture and implementation claims; date is the first preprint submission.
Published 2011-09-07 · Checked 2026-09-20