# Glossary

URL: https://docs.nexart.io/docs/glossary

Short, precise definitions for the vocabulary used across the NexArt docs, each linked to the page that owns the concept.

## AIEF

A framework projection that verifies an AI Execution CER (V1 or V2) and returns a single PASS/FAIL result with a reason and four checks. See AIEF.

## Attestation

A signed receipt issued by the NexArt attestation node witnessing that a producer-sealed artifact existed at a point in time. The node never creates or replaces `certificateHash`. See AI Execution CER.

## Canonicalisation

The deterministic, byte-level serialization applied to a bundle before hashing. Profiles include `nexart-v1` and `jcs-v1`, each bound to a specific `protocolVersion`. See Versions.

## CER (Certified Execution Record)

The smallest unit of proof in NexArt: a tamper-evident record of a single AI execution step, identified by its `certificateHash`. See AI Execution CER.

## certificateHash

SHA-256 hash computed over a CER's canonical bundle. It is the canonical identity of a CER. See AI Execution CER.

## Commitment

A one-way HMAC-SHA256 binding of a field's content plus a random salt,`"hmac-sha256:" + hex(...)`, used in confidential mode. Not encryption: it never reveals or recovers the original value on its own. See AIEF.

## Confidential Mode

Sealing selected fields (`input`, `output`, `instruction`, or a `decisionRef`) as commitments instead of plaintext. See AIEF.

## decisionRef

A reference to a decision input, either public (`refForm: 'public'`) or opaque as a commitment (`refForm: 'commitment'`). Opacity is not confidentiality on its own. See AI Execution CER.

## executionRole

A required, producer-declared field on a V2 snapshot: `'advisory' | 'operative' | 'unspecified'`. NexArt never infers this value. See AI Execution CER.

## instructionKind

Required when `instruction` is present, forbidden otherwise: `'system' | 'derived' | 'label'`. See AI Execution CER.

## Integrity vs Authenticity

Integrity means the artifact was not modified since it was sealed. Authenticity means the artifact can be attributed to a specific signer (for example, via node attestation). A bundle can have integrity without an attached attestation. See AIEF.

## jcs-v1 / nexart-v1

The two canonicalisation profiles currently supported, each bound to specific protocolVersion values. See Versions.

## modelEvidence

An optional V2 snapshot field carrying producer-transcribed evidence about a model response. It is never provider-signed proof, and it never overwrites the producer-declared `model` field. See AI Execution CER.

## Opening

The `{ field, salt, scheme }` needed to reveal a commitment for selective disclosure. Openings are never stored in the CER; the producer keeps them. See AIEF.

## Producer-First

The principle that the producer computes and owns `certificateHash` before any node is involved; the node only attests to what already exists. See AI Execution CER.

## projectHash

A hash binding the ordered step registry of a Project Bundle. See Versions.

## Project Bundle

A container (`cer.project.bundle.v1`) composing multiple CERs (V1, V2, or a mix) into one verifiable, ordered workflow. See AI Execution CER.

## protectedSet

An SDK-derived list of sorted field paths sealed inside a V2 bundle's `certificateHash`, never caller-supplied. See AI Execution CER.

## protocolVersion

The canonicalisation protocol version carried in a snapshot or bundle. An unrecognized value MUST be rejected (fail closed). See Versions.

## Receipt

The node's signed attestation response for a sealed artifact, added under `meta.attestation` after sealing. See AI Execution CER.

## RFC 3161 Trusted Timestamp

A third-party timestamp authority's cryptographic proof that data existed at a given time, used as supplemental timestamp evidence. See Versions.

## Salt

Random bytes mixed into a commitment's HMAC key to prevent brute-force guessing of low-entropy values. See AIEF.

## Sealing

The act of computing `certificateHash` and finalizing a bundle so it becomes independently verifiable. See AI Execution CER.

## Snapshot

The recorded execution fields inside a CER, before sealing. See AI Execution CER.

## Verdict

An evaluation outcome. In verification, a success verdict is `'VERIFIED' | 'VERIFIED_CONFIDENTIAL'`. In the Policy SDK, a verdict is `'PASS' | 'FAIL' | 'ERROR'`, with `ERROR` distinct from `FAIL`. See Policy SDK.

## Next

- AI Execution CER
- AIEF
- Policy SDK
- Versions