Post-quantum crypto on a radio link fails off a 0.16 dB cliff
Hold ~2 dB of link-budget margin above the error-correction waterfall so the post-quantum handshake never falls off the cliff.
An optimized post-quantum key exchange (ML-KEM) over an error-corrected radio link works flawlessly — until signal quality drops through a razor-thin threshold, where it fails…
Full framing
Hold ~2 dB of link-budget margin above the error-correction waterfall so the post-quantum handshake never falls off the cliff.
An optimized post-quantum key exchange (ML-KEM) over an error-corrected radio link works flawlessly — until signal quality drops through a razor-thin threshold, where it fails 100% of handshakes. That cliff sits right where an ordinary voice call still sounds fine, so a jammer needs only ~0.3 dB of added noise to silently kill the encryption while everything else looks normal.
Public-news source spine
The public record behind the subject
Claim-bound findings What the evidence supports—and how strongly 3 bound claims
- supported
Between Eb/N0 ≈ 1.2 dB and ≈ 1.8 dB the ML-KEM handshake goes from 100% failure to 0% — a 0.16 dB-wide cliff, not a gradual degradation.
- supported
One residual bit error anywhere in the multi-kilobyte ciphertext frame collapses the lattice decapsulation, so the post-FEC frame-error rate must be driven to ~0 — far stricter…
Full claim wording
One residual bit error anywhere in the multi-kilobyte ciphertext frame collapses the lattice decapsulation, so the post-FEC frame-error rate must be driven to ~0 — far stricter than the 1e-3 a voice or video link tolerates.
- supported
The cliff lands ~0.3 dB above where a voice-grade link is still fine, so degrading the channel just past voice quality silently breaks the crypto — the decryption-failure attack…
Full claim wording
The cliff lands ~0.3 dB above where a voice-grade link is still fine, so degrading the channel just past voice quality silently breaks the crypto — the decryption-failure attack surface.
Executive readout
Decision summary
Supported finding
- Optimized post-quantum crypto over a contested radio link is a cliff, not a slope. Size the FEC and link budget to keep ~2 dB of margin above the error-correction waterfall — the…
Review 1 full note
- Optimized post-quantum crypto over a contested radio link is a cliff, not a slope. Size the FEC and link budget to keep ~2 dB of margin above the error-correction waterfall — the handshake has no graceful-degradation region to fall back on.
Decision boundary
- The cliff position (≈1.2–1.8 dB) comes from a calibrated LDPC waterfall surrogate, not a full belief-propagation decoder; the exact dB will shift with a real code, interleaver,…
Review 1 full note
- The cliff position (≈1.2–1.8 dB) comes from a calibrated LDPC waterfall surrogate, not a full belief-propagation decoder; the exact dB will shift with a real code, interleaver, and channel. The SHAPE — a near-vertical, all-or-nothing failure — is intrinsic to the lattice frame rule and does not.
Question to resolve
- Which LDPC base graph and modulation your tactical waveform actually uses, and whether adaptive coding can step down fast enough to stay off the cliff during an active…
Review 1 full note
- Which LDPC base graph and modulation your tactical waveform actually uses, and whether adaptive coding can step down fast enough to stay off the cliff during an active decryption-failure jammer.
How this was governed · bronze agent credential
50% autonomous · 2 human checkpoints (intake (Gate A) & Gate B sign-off)
Verification
- Supported claims3
- Projected0
- Illustrative0
Evidence
- Cited (source)1
- Modeled1
- Observational0