Open-Source Content Provenance

Prove the origin of AI content

OriginMark adds a tamper-evident cryptographic signature to any AI-generated artifact. Sign content with Ed25519, export C2PA-aligned manifests, and verify authenticity in milliseconds.

Ed25519 SignaturesSHA-256 ChecksumsC2PA JSON Export

provenance_inspector.ts

Verified Authenticity

generative_blueprint.webp

SHA-256: 8f9b2d4c...e137a

2.4 MB

Author IdentityElena Vance

AlgorithmEd25519

originmark.verify.json

{
  "content_hash": "8f9b2d4c...e137a",
  "algorithm": "Ed25519",
  "status": "VALID_AUTHENTIC",
  "timestamp": "2026-09-19T11:30:00Z"
}

Cryptographic signature verifiedEd25519 Signature Check

MIT License

Open Source

Ed25519

Cryptography

SHA-256

Content Integrity

C2PA v1.4

Manifest Export

How it works

Three simple steps to generate and verify tamper-evident cryptographic proof.

STEP 01

Upload Artifact

Select or drop any AI-generated image, markdown text, or code artifact. OriginMark calculates the cryptographic SHA-256 hash of the content.

sha256(artifact) -> 8f9b2d...

STEP 02

Sign with Ed25519

Generate an Ed25519 digital signature over the content hash. Author identity and model metadata are packaged alongside the signature in a portable JSON sidecar.

ed25519.sign(hash, secretKey)

STEP 03

Verify Anywhere

Distribute the .originmark.json sidecar alongside your content. Anyone can independently verify authenticity without an account or central authority.

ed25519.verify(hash, sig, pubKey)

Engineered for AI provenance

Built for automated pipelines, creative platforms, and open content verification.

Batch Artifact Signing

Queue and sign multiple artifacts in a single workflow. Drop multiple images or text files into the web workspace or automate processing via the async FastAPI backend.

Async FastAPI BackendBulk Sidecar Download

Ed25519 Signatures

High-performance Edwards-curve digital signatures (via PyNaCl / libsodium) providing ~128-bit classical security and compact 64-byte signatures.

RFC 8032 Compliant

Independent Verifiability

Verify artifacts directly in the web dashboard or against the self-hostable API without needing an account or API key. All cryptographic keys are included in the sidecar.

Open & Self-Hostable

RESTful FastAPI

API-First Architecture & C2PA Export

Export C2PA v1.4 JSON manifests for standardized provenance tracking. Automate signing and verification workflows with the FastAPI REST endpoints.

curl -X POST http://localhost:8000/sign \
  -F "file=@model_output.png" \
  -F "author=Alice Freeman"

FastAPI Backend + Ed25519 CryptographyDeveloper Guide

Provenance Metadata Tracking

Bind creator identity, AI model name, timestamp, and signed content hashes into a structured, verifiable sidecar manifest.

authormodel_usedtimestamp