Terminology
The words this repository refuses to use loosely.
Short, so that it is actually read. Where a term already has a standard meaning in the literature, we use the standard meaning and say so rather than inventing a synonym.
Economic units (inherited from Nodus v1)
| Term | Meaning |
|---|---|
| CU | Compute Unit. A quantity of computational work. CU-v0 = 100 tokens of a fixed reference workload (../nodus/shared/cu.py). |
| CC | Compute Credit. The transferable accounting unit, integer micro-credits. |
| CU-v0 | The current, workload-anchored definition. Its weakness: model_weight is DECLARED, and token counts are provider-reported. |
| Verified CU (vCU) | New here. A CU for which evidence at a stated level supports a stated claim set. vCU is always qualified: "vCU(A, L3, 2^-40)" means one CU whose correctness is supported by an L3 mechanism with soundness error 2^-40. An unqualified "verified CU" is meaningless. |
| Cost of verified CU | cost(CU) + cost(evidence). The metric the whole programme optimises. |
Verification vocabulary
| Term | Meaning |
|---|---|
| Claim O/A/B/C/D/E | Origin / Correctness / Execution / Work / Physical resource / Useful computation. Defined in verification-taxonomy.md. |
| L0–L6 | Evidence strength ladder, from bare assertion to unconditional. |
| Proof | Reserved for L5/L6. Never used for a random audit. |
| Check | An L2/L3 mechanism. Has a soundness error, which must be quoted. |
| Attestation | A signed statement by a hardware root of trust (L4). Not a proof. |
| Receipt | An authenticated summary of a claimed execution (L1). What v1 has. |
| Soundness error | Probability that a cheating prover is accepted, per check. |
R |
cost of evidence / cost of native computation. The headline metric. |
R_prove / R_verify |
The provider-side and verifier-side components of R. R_verify is the one that decides whether a scheme beats re-execution. |
| Re-execution baseline | Running the job again. R_verify = 1 by definition. Every mechanism is quoted against it. |
| Model binding | Cryptographically tying evidence to specific weights, usually via a commitment. Without it, model substitution is undetectable. |
| Freshness binding | Tying evidence to this execution occasion, usually via an unpredictable value chosen after job assignment. Without it, cached results and precomputation are undetectable. |
Evidence labels
Inherited from ../nodus/PAPER_BRIEF.md and used identically here:
- MEASURED — we ran it and recorded it.
- DERIVED — computed from measured values; the derivation is shown.
- DECLARED — a human chose the number. Always flagged.
- SPECULATIVE — a plausible idea with no evidence.
- UNKNOWN — we looked and do not know. Preferred over a guess.