VeraFile

Verify a file from a portable proof artifact in one command.

npx verafile verify file.pdf proof.json

Output:

VALID

or:

INVALID

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What VeraFile Does

VeraFile recomputes the SHA-256 hash of a local file and compares it against the hash stored in a proof JSON file.

If one byte changes, verification fails.

Verification is independent of the originating system.

No API required.

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Example Proof

{
  "hash": "0x..."
}

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Quick Start

Run directly with NPX:

npx verafile verify example.txt example.proof.json

Modify the file:

echo change >> example.txt

Verify again:

npx verafile verify example.txt example.proof.json

Result:

INVALID

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Install

npm install -g verafile

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Local Development

npm install
npm run build
node dist/cli.js verify example.txt example.proof.json

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Relationship to OCP

VeraFile is a minimal CLI implementation inspired by the Observation Commitment Protocol (OCP).

OCP defines a minimal verification model:

data → digest → public commitment
recompute → compare → confirm inclusion

This CLI currently verifies the file-to-digest step.

Future implementations may additionally verify ledger inclusion and commitment proofs.

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Links

OCP Repository: https://github.com/damonzwicker/observation-commitment-protocol

Live Demo: https://observation-commitment-protocol.vercel.app/

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License

MIT