[ PROOFECONOMY ]™GlossaryOriginSpecsFidelity-at-Capture
Fidelity-at-capture is the property that evidence faithfully represents what the executor actually did, established through structural independence at the moment of capture rather than through tamper-evidence after the fact.
What it means
Two different questions get asked about evidence:
- Consistency-of-data: once captured, did the evidence stay intact?
- Fidelity-at-capture: was the evidence faithful to begin with, or did the party being evaluated shape what got captured?
Almost every corroboration model answers the first question. Fidelity-at-capture is the second.
Why integrity is not enough
Cryptographic integrity proves a record was not altered after the fact. It says nothing about who generated the record, under what incentive, or with what access to shape the input. A hash chain on a self-generated log is still a self-generated log. Sealing it anyway is stupid cryptography.
The four properties
| Property | What it establishes |
|---|---|
| Structural Independence | The capturing party has no outcome-contingent stake in, and no control ceded to or from, the party being measured. |
| Fidelity-at-Capture | The evidence represents what actually happened, because the capture was independent. |
| Cryptographic Integrity | The evidence cannot be altered after capture without detection. Necessary, not sufficient. |
| Consistency-of-Data | The evidence stays internally consistent from capture forward. What most tier models actually measure. |
Relation to the five-tier model
The Proof Economy’s corroboration tiers (Activated, Committed, Witnessed, Analyzed, Sealed) describe what happens to evidence once it exists. Fidelity-at-capture is the precondition for Witnessed and Sealed to carry any evidentiary weight. A Sealed record built on a self-attested capture is a well-preserved unreliable record.
Distinguishing note
Same-host observability (for example, an eBPF daemon run by the same operator as the agent it watches) solves signal correlation: what happened. It does not establish origination independence, because it trusts the operator running the observer. Correlation tells you what happened. Structural independence tells you whether you can believe who is telling you.
Where the term comes from
Defined in Proof Protocol specification PP-SPEC-023, Structural Independence and the Fidelity-at-Capture Requirement, by Craig Thomas Ellrod, published 17 September 2026 and archived at Zenodo, DOI 10.5281/zenodo.22821379.
Related terms
- Dead Canary Protocol (ProofSwarm)
- Five-Tier Corroboration
- Proof Economy Universal Framework
- Proof of Efficacy
- Self-Attestation Oxymoron (SAO)
- Structural Independence
- Stupid Cryptography