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Evident ICU

Integrity model

Verification without overclaiming.

Evident ICU treats file identity, provenance, custody, authenticity, and admissibility as related but different questions. A technical signal is useful only when its limits remain visible.

Four layers

What each layer can help establish.

Digest

Byte identity

A recomputed SHA-256 value can show whether the current bytes match a previously recorded value.

Provenance

Source relationship

A provenance record describes which sources and transformations produced a derivative.

Custody

Handling history

An attributable event log can record access, transformation, review, and export activity.

Foundation

Human context

People and institutions still evaluate collection, authorship, completeness, relevance, and legal foundation.

SHA-256

A precise answer to a narrow question.

When the same bytes produce the same digest, a reviewer has a strong technical basis for saying those bytes match the bytes used to compute the recorded digest. That is valuable for integrity comparison.

It does not answer:

  • Who created the material or when it was actually created.
  • Whether the source is complete, accurate, lawful, or authentic.
  • Whether metadata was accurate before intake.
  • Whether a court or agency will accept the material.
record_id
SYN-SRC-0012
algorithm
SHA-256
digest
6c9a…4f21 (synthetic)
captured_at
illustrative UTC timestamp
meaning
byte comparison only

Custody history

Add events. Preserve corrections.

The governing design uses append-only custody and correction patterns: later events can explain or supersede earlier entries without pretending the earlier history never existed. Public service behavior still requires environment-specific verification before reliance.

  1. Intake recorded

    Identify the source, actor, time, and digest metadata.

  2. Transformation linked

    Record the source relationship and process used to create a derivative.

  3. Review attributed

    Associate notes, disputes, corrections, and approval states with a reviewer.

  4. Package assembled

    Record the package identity, included records, manifest information, and known limitations.

Boundaries

Integrity is necessary. It is not a verdict.

  • No technical record can independently prove the truth of every statement inside a file.
  • Custody logs are only as complete as the systems and people that record the relevant events.
  • Independent verification requires access to the compared bytes, digest, method, and context.
  • Authentication and admissibility remain legal and factual determinations made by people with authority.