Does giving a Markov chain dwell times or a second-order memory let it fool a webcam-signal detector?

What it found

The predecessor project's first-order Markov chains over DUX webcam-signal frames were caught at AUROC 1.000. Two fixes it named are tried here: a semi-Markov chain that holds each k-means state for a dwell time drawn from that state's empirical run lengths, and a second-order chain whose next state depends on the last two (backing off to first order for unseen pairs). With 8 or 32 states, fitted on one person's earlier windows or on the other 45 people's, emitting state centres or real frames, all 16 cells are scored at AUROC 0.999 to 1.000 by a boosted-tree detector over 3 seeds, in the population and profile-aware detectors alike. Neither fix reaches the 0.57 to 0.65 of stitching 50-frame real blocks. Stylised: one form-filling context, 46 people, k of 8 and 32 only, empirical dwell times without drift.

A figure from its own output

Paper, code and results

• README and method
• Experiments and results
• Tests

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Other research topics

Proper scoring & elicitation28Effort & peer prediction9Verification games & slashing19Detection & tolerances14Markets as routers13Prediction-market design9Paying contributors8Decentralised training systems23Digital twins & sim-to-real164LLM chip design loops40Robot manufacturing loops53Ambient AI assistant46Self-replicating manufacturing34Simulation-first design64Engineered clothing45Task-specific AI accelerators40Algorithmic chip-design loops42Open-source purpose-built robots44The software-engineering loop43Adversarial human imitation41Open-source residential construction41Autonomous multi-angle capture34Sensing, imaging and 3D31Energy supply and dense energy storage39Robot societies among people31Agentic co-design of low-cost robots27Laundry-hanging robots25Machine learning on qualitative data23Robots on the building site27Civilizations & group psychology1History & human sciences1

Produced with AI assistance (Claude). Results are from the code in this repository and are simulated or stylised unless the abstract says otherwise; nothing here implies affiliation with or endorsement by any lab, researcher or company cited. MIT licensed.