Verify a Certificate of Authenticity

EXP0 allows anyone to verify the authenticity of an artwork in seconds. This verification confirms that the artwork is original and has not been modified.

Verification Methods

1. By Image

The simplest method: upload the image to verify.

1. Go to exp0.xyz/verify
2. Click on “Verify an artwork”
3. Upload the image file (JPEG, PNG, TIFF, WebP)
4. EXP0 calculates the fingerprint and searches for a corresponding certificate

Result:

• ✅ Certificate found: The artwork is authentic, with creator details
• ❌ No certificate: The artwork is not certified or has been modified

2. By SHA-256 Hash

If you know the digital fingerprint of the artwork:

1. Go to exp0.xyz/verify
2. Select the “Hash” tab
3. Paste the SHA-256 fingerprint (64 characters)
4. Click “Verify”

Example hash:
a7f5c3d2e1b9f8a4c6d2e5f1a3b7c9d2e4f6a8b1c3d5e7f9a2b4c6d8e1f3a5b7

3. By QR Code

Physical prints and PDF certificates include a QR code:

1. Scan the QR code with your smartphone
2. You are redirected to the verification page
3. Certificate information is displayed automatically

4. By Certificate ID

Each certificate has a unique identifier:

1. Go to exp0.xyz/verify
2. Select the “ID” tab
3. Enter the certificate identifier (e.g., EXP0-2024-A7F5C3D2)
4. View the certificate details

Blockchain Verification (NFT)

For artworks sold with an NFT, verification is enhanced by the blockchain.

Verifiable Information

Verify on Polygonscan

1. Click “View on blockchain” from the verification page
2. View token details on Polygonscan
3. Check IPFS metadata (link in tokenURI)

Verify IPFS Metadata

NFT metadata is permanently stored on IPFS:

{
  "name": "Artwork title",
  "description": "Description...",
  "image": "ipfs://Qm...",
  "properties": {
    "content_hash": "a7f5c3d2e1b9f8a4...",
    "edition": { "number": 1, "total": 10 },
    "creator": "0x..."
  }
}

The content_hash field must match the calculated hash of the image.

What to Verify?

For Buyers

Before acquiring an artwork, verify:

• [ ] The certificate exists and is valid
• [ ] The displayed creator matches the seller or announced artist
• [ ] The creation date is consistent
• [ ] For an NFT: the token exists on the blockchain
• [ ] The edition number matches (e.g., 3/10)

For Collectors

During a resale, make sure that:

• [ ] The image fingerprint matches the certificate
• [ ] The file has not been modified (even slightly)
• [ ] The ownership history is traceable (for NFTs)

Why Verification Fails?

Modified Image

Any modification, even minor, changes the fingerprint:

• Resizing
• Compression
• Adding watermark
• Modifying EXIF metadata
• Format conversion

Always use the original file provided by the artist.

Certificate Not Created

The artist may not have certified this artwork on EXP0 yet.

Fake Certificate

If the displayed certificate does not match EXP0 verification, the artwork or certificate could be counterfeit.

Verification API

For developers and partners, EXP0 offers a verification API:

# Verify by hash
GET /api/v1/certificates/verify?hash=a7f5c3d2...

# Response
{
  "verified": true,
  "certificate": {
    "id": "EXP0-2024-A7F5C3D2",
    "creator": "artistname",
    "created_at": "2024-03-15T10:30:00Z",
    "edition": { "number": 1, "total": 10 },
    "blockchain": {
      "network": "polygon",
      "contract": "0x...",
      "tokenId": "12345"
    }
  }
}

Frequently Asked Questions

Must the verified image be pixel-perfect?

Yes. The SHA-256 hash is extremely sensitive: a single modified bit produces a completely different fingerprint. This is what guarantees the integrity of the artwork.

Can I verify a screenshot?

No. A screenshot will never have the same hash as the original file. Always request the source file from the artist.

Is verification free?

Yes, verification is free and accessible to everyone, even without an EXP0 account.

How do I prove that I am the owner?

For NFTs, connect your wallet to EXP0. The system will automatically verify that you own the corresponding token.