SWARMCD


Early bitcoin NFTs were not immutable.

In November 2015, XCPCARDS.com solved this for several cards, SWARMCD included.

This was achieved by including the following text in a bitcoin transaction:

xcpcards.com/SWARMCD EfUYV6Ec

The identifier EfUYV6Ec is the jpeg's checksum which proves the card's design. Since this text is engraved on the blockchain, the proof can never be tampered with, nor can the timestamp be disputed.

This makes SWARMCD one of the first real crypto cards!

Techincal Details

The file's full sha-256 hash in hex and base64 encodings:
11f51857a11ce6750c29cdd46a1b0fab12d26530a673b17646614bb206f8dc4a
EfUYV6Ec5nUMKc3UahsPqxLSZTCmc7F2RmFLsgb43Eo=

The identifier is a 48 bit truncated hash.

This is sufficiently strong, yet short enough to have the text fit inside a Bitcoin op_return message.

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Full Set of Cards

The below cards were notarized by XCPCARDs.com

Most are from the Spells of Genesis project.

Click a card to view its details.