Two-Stage Continuity Verification

01 — Question

Can a strong presence signal compensate for an incomplete continuity challenge?

Broader — can temporal continuity provide a verification property that static identity alone cannot?

This note reports a small real-device experiment that addresses only the first. The second is Continuity Lab's larger research question; these four trials do not settle it.

02 — Experiment

Four trials (A–D) on a single physical device, single session, single participant. Two-stage decision rule: stage 1 requires EE-001 ≥ 0.50; stage 2 requires EE-003 = 1.000 — all three prompted rotations, each in the prompted direction at ≥ 40°/s. Both stages are mandatory.

Decisive case — D

03 — What Happened

In Test D, EE-001 = 0.800 cleared the Stage-1 presence threshold, but the two-stage rule requires both stages. So 2/3 is not 0.667 — it is a failed challenge (EE-003 = 0.000). Presence evidence passing Stage 1 did not compensate for challenge completion failing Stage 2.

04 — Observation

05 — Limitations / Non-Claims

n = 4 · 1 device · 1 session · 1 participant

• Not a security proof.
• Not a false-acceptance-rate (FAR) or false-rejection-rate (FRR) benchmark.
• Does not demonstrate spoof resistance.
• Does not establish generalization across devices, users, environments, or motion patterns.