Bull on Fire Record of Ownership

The Certificate of Authenticity (COA) is linked to an NFC tag attached to the artwork. Anyone can view the COA's details by scanning the tag with their mobile device. The tag is password protected so that only the work's owner can update its contents.

The COA contains general artwork details, including title, artist name, artist signature, medium, dimensions, edition number, total editions, and images.

The COA also contains unique fields that use Bitcoin to prove the work's attributes:

• Creator Address: A public Bitcoin address owned by the artist. Only the artist can prove they are the work's creator by signing a message with the address' private key.
• Records of the original COA's creation (view here)
  • The hash of the document's IPFS storage address
  • The SHA-256 hash of the document
  • The Bitcoin block that includes the document's SHA-256 hash and the date and time at which it was added to the blockchain
• Records of the artwork's purchase
  • The SHA-256 hash of the Transaction ID of the artwork's purchase
  • The SHA-256 hash of the transaction's Previous Output Address, owned by the purchaser
  • The amount of bitcoin paid for the artwork

A prospective secondary market buyer of the artwork can request the current owner to provide the unhashed Transaction ID and Previous Output Address to prove they are the work's true owner. For extra assurance, the current owner can sign a message with the Previous Output Address' private key. The value of the transaction can also be verified with the consideration that the amount is adjusted for the bid deposits paid during the auction and shipping charges.

The COA has been included in a Bitcoin transaction through opentimestamps.org to prove the document existed, in its exact form, prior to its recording to the blockchain. Anyone can upload the COA and its corresponding .ots file to verify the timestamp.

Scarce City and the artist broadcast the COA's unique SHA256 hash through their website and social channels so that anyone can verify the COA's authenticity. If you are presented with a COA that generates a hash that differs from the broadcasted hash, the COA is not authentic.