Setting the stake too low let attackers earn a 235% return
The most counterintuitive result of the 14 mechanism simulations: free entry blocks completely, yet a stake of 2 gave the attacker a return per unit of cost of 2.354. We deleted two defense designs (an exogenous entry fee and endorser liability) entirely.
On 2026-07-26, we ran 14 mechanism simulations (E1–E9, E12–E16) to ask a very ordinary question:
How much entry fee should we charge an attacker so that attacking doesn't pay?
The answer: don't charge one.
#Design
| Honest residents | 5, each with a real Ed25519 identity + a real event chain + a real capability card |
| Attacker | 1 |
| Warm-up | 8 rounds, so the ecosystem has records that can be endorsed |
| Total rounds | 400 |
| Seeds | 20 per cell (40 for E9, 30 for E15) |
| Audit rate | 0.2 (0.05 from E2/E3 on) |
| Reviewer accuracy | 0.7 (chosen by the author, not measured) |
#Result: the smaller the stake, the safer
| Exogenous stake | Attacker hits | Return | Full-block rate |
|---|---|---|---|
| stake = 0 | 0.00 | — | 100% |
| stake = 2 | 5.00 | 2.354 | 0% |
| stake = 5 | 3.05 | 0.560 | — |
| stake = 10 | 1.95 | 0.177 | — |
| stake = 20 | 1.90 | 0.092 | — |
#Why this happens
#Probation: all the value is in the first step
| Probation length m | Attacker hits | Full-block rate |
|---|---|---|
| m = 0 | 6.85 ± 1.80 | 0% |
| m = 1 | 0.00 | 100% |
| m = 2 | 0.00 | 100% |
| m = 3 | 0.00 | 100% |
| m = 5 | 0.00 | 100% |
| m = 8 | 0.00 | 100% |
In one sentence: all of the defensive value is in the m = 0 → 1 step. Lengthening probation adds no gain at all.
#Endorser liability: a pure loss
| Liability coefficient λ | Attacker gain | Honest participants' loss |
|---|---|---|
| λ = 1.0 | 0 | 0.000 |
| λ = 0.9 | 0 | 0.691 |
| λ = 0.7 | 0 | 0.702 |
| λ = 0.5 | 0 | 0.702 |
| λ = 0.3 | 0 | 0.702 |
A head-to-head of the three designs (E6):
| Design | Attacker hits | Full-block rate | Honest participants' loss |
|---|---|---|---|
| Free | 0.00 | 100% | 0.000 |
| Stake 5 | 3.05 | 0% | — |
| Stake 10 | 2.00 | 0% | — |
| Endorsement λ=0.5 | 0.00 | 100% | 0.702 |
#Against a patient attacker: all three paths are the same
E7 asks: with free entry, what happens against a "patient" attacker?
| Design | Attacker hits |
|---|---|
| Free | 1.65 ± 0.73 |
| Stake 10 | 1.70 ± 0.64 |
| Endorsement | 2.00 ± 0.00 |
All within the margin of error. Under this condition the stake does nothing at all.
E8 sweeps ecosystem size (2 / 3 / 5 / 10 / 20 honest participants): all 0.00, 100% fully blocked. Free entry holds at every size.
E9 sweeps robustness (40 seeds): 0.00 ± 0.00, min 0, max 0.
#Verdict
Neither path — an exogenous entry fee or endorser liability — should be taken. The premise is wrong.
We deleted both mechanisms. Not because they have "a weaker effect," but because one of them is actively harmful and the other is a pure loss.
#What we did not measure
#Next
- The constraint that is truly tight: reviewer-accuracy-binds
- What this system actually relies on to stop attackers: Defense axis
