Prepare-and-measure QKD
Decoy-state BB84
Decoy intensities help estimate single-photon yields for weak coherent sources.
Core idea
Signal and decoy pulses reveal whether channel behavior depends suspiciously on photon number.
Minimal mathematics
The MVP uses a pedagogical lower-bound proxy for Q1 and e1 rather than a full finite-key decoy analysis.
Typical assumptions
- Intensity settings are characterized
- Decoy statistics are simplified
- Side-channel leakage is not modeled
Common failure modes
- Source intensity modulation flaws
- Finite statistics
- Detector side channels
Related tools
References
- Hwang decoy-state method
- Lo, Ma, and Chen decoy-state QKD