Legal Evidence — SHA-256 Tamper-Evident Chain

What it is

SHA-256 hash chain: each exhibit links to the hash of the previous one — tamper-evident. SHA-256 Tamper-Evident Chain is a core component of the P31 Labs sovereign cognitive infrastructure stack — built to run offline, deployed to the edge, and designed without dark patterns.

WebCrypto SubtleCrypto.digest() computes SHA-256 in-browser. The chain is a linked list of {hash, prevHash, data} objects stored in localStorage and exported as a signed JSON bundle. This tool documents your own exhibits — not legal advice. Short p31ca.org URL 302 → workers.dev (probe: worker-spa-legal-evidence).

Core features

SHA-256 hash chain: each exhibit links to the hash of the previous one — tamper-evident

Exhibit fields: date, description, file reference, category (legal/medical/financial)

Structured JSON export with hash-chain verification helpers — admissibility depends on jurisdiction and counsel; not a guarantee

QR code generation for each exhibit — print and attach to physical filing

Batch import from CSV for bulk evidence ingestion

How to use

1Add an exhibit: fill in date, description, and category — SHA-256 is computed automatically

2The chain viewer shows every exhibit linked to the one before it

3Export the full chain as JSON — the verification proof can be independently confirmed

Architecture

P31 Labs, Inc. (Georgia nonprofit, EIN 42-1888158) builds open tools for cognitive sovereignty, communication clarity, and family coordination. This page is technical documentation, not medical or legal advice. Mission and support: phosphorus31.org.

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