Quorum and audits
tasqnetwork.io/benchmark/quorum
Mode R accepts a result when q of r independent seats agree. These simulations check the capture formula (Eq. 6), the distinct-machine rule, and the economics of an adversary that controls several seats. The attack simulation is what exposed a flaw in the first design: with public seat selection a coordinating adversary profits at any unit value. Hidden audits fixed it.
Capture probability: Eq. 6 against simulation
Dots are simulated with uniform seat selection, dashed lines are Eq. 6. Stake-weighted results are in the CSV.
Source: S1_quorum_capture.csv, sim_protocol.py
Distinct-machine rule
| Identities per machine | Identity share ρ | Capture without rule | Capture with rule | Trials |
|---|---|---|---|---|
| 1 | 0.1 | 0.0277 | 0.0277 | 30,000 |
| 1 | 0.2 | 0.1033 | 0.1033 | 30,000 |
| 1 | 0.3 | 0.2153 | 0.2153 | 30,000 |
| 2 | 0.1 | 0.0291 | 0.0288 | 30,000 |
| 2 | 0.2 | 0.1035 | 0.1029 | 30,000 |
| 2 | 0.3 | 0.2145 | 0.2142 | 30,000 |
| 4 | 0.1 | 0.0277 | 0.0271 | 30,000 |
| 4 | 0.2 | 0.1044 | 0.1033 | 30,000 |
| 4 | 0.3 | 0.2154 | 0.2144 | 30,000 |
| 8 | 0.1 | 0.0280 | 0.0258 | 30,000 |
| 8 | 0.2 | 0.1026 | 0.1001 | 30,000 |
| 8 | 0.3 | 0.2180 | 0.2150 | 30,000 |
The rule stops one machine from filling several seats of the same unit. Its effect grows with the number of identities per machine: at 8 per machine and ρ = 0.1 it lowers capture from 2.8% to 2.6%. It is a backstop, not the main defence. Hidden audits are.
Source: S2_distinct_machines.csv
Attack economics with hidden audits
Coordinating adversary with ρ = 0.1, r = 3, q = 2. Profit above zero means the attack pays. Without audits it pays at every value.
Source: S3_attack_economics.csv
Break-even value versus the admission rule
| Audit rate π | Simulated break-even V / σS | Eq. 7 rule | Difference |
|---|---|---|---|
| 0.05 | 0.110 | 0.105 | 4.5% |
| 0.1 | 0.226 | 0.222 | 1.5% |
| 0.2 | 0.504 | 0.500 | 0.8% |
| 0.3 | 0.862 | 0.857 | 0.6% |
The rule V ≤ πqσS / (1 − π) sits slightly below the simulated break-even at every audit rate, so it errs on the safe side.
Source: S3b_breakeven.csv