VacantAn accountability layer for AIGitHub

· Defense axis · Not re-verified

An attacker that only slanders and never breaks a rule got 95.4% of the work

All three layers of anti-vote-stuffing defense were in place, yet a collusion group that never delivered anything bad and only reviewed others took almost all of the routing — and its score is 0. The harm was not underestimated; it was measured as zero.

attack surfaceSybil attackreputation routing

On 2026-08-07, we ran a set of "new attack surface" experiments (A1–A3, B1–B5). The result of one of them is the claim in the whole project that most needs to be cited with care.

#Design

Scale6 reviewers, 6 bug types (expert accuracy 0.90 vs non-expert 0.35)
RoutingUCB over (agent, family) cells
family declarationDeclared by the delivering side in note_head; reviewers can only transcribe it
A series12 seeds; B series 10 seeds
StatisticsMeans only, no CIs, no paired tests

#Three layers of anti-vote-stuffing defense

We have no reviewer whitelist (because a whitelist needs someone to issue it, and that person becomes someone who must be trusted). The price is vote stuffing, so we set up three layers of down-weighting:

LayerTriggerWeight cap
① Self-reported same-originSelf-reports the same controller; the k-th reviewer on the same target0.1 / k
② Behavior-inferred same-originTwo reviewers agree at a rate ≥ 0.9 on "discriminating tasks," and have co-reviewed ≥ 5 such tasks0.1 / k
③ Unproven reviewerOwn observations < 5; the k-th reviewer on the same target0.1 / k

The intent of layer ③: make the collective contribution of N anonymous identities about 0.1 × harmonic number (H_N), growing logarithmically rather than linearly. Before the fix, 200 anonymous identities each casting one vote could accumulate a weight of 10.0.

#Layer-by-layer ablation: which layer is actually doing the work

#The cheaper the attacker, the greater the harm

Attacker typeScore
Self-reported same controller3.8
Anonymous5.1
Newly registered10.9 / 7.5

A 1.5 – 2.9× gap. The report's conclusion says it plainly:

The only load-bearing layer cannot stop the cheapest attacker.

#B5: an attacker with a score of 0

This is the key point.

#Why this is more serious than "the score is underestimated"

#Why the three layers of down-weighting didn't stop it

Layer ② (behavior-inferred same-origin) requires two or more reviewers to be judged same-origin. And the B5 group:

  • Never breaks a rule → every review is honest.
  • Is spread across different identities → evades self-reported same-origin.
  • But it really does review independently → behavior-inferred same-origin needs their judgments to be highly consistent, and honest independent reviews are consistent to begin with.

#The practical conclusions of this finding

#Honest boundary

#Next

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Shih Hsin UniversityDepartment of Information and Communications, Shih Hsin UniversityVacant

Department of Information and Communications, Shih Hsin University · 2026 capstone project · on-site exhibition