Curio Cards art token for Card #11 (BTC Keys), art by Cryptograffiti.
Historical Significance
Part of Curio Cards, the first art show NFT collection on Ethereum and an early model for fixed-supply digital art ownership.
Context
Curio Cards launched as an online Ethereum art gallery in May 2017, before ERC-721 was widely adopted. This contract belongs to the original release set and was deployed by Rhett Creighton (@rhett_creighton), Curio Cards co-founder and Solidity developer. Published Jun-06-2017 06:31:38 PM +UTC.

Curio Card #11 artwork: BTC Keys by Cryptograffiti.
Source: Curio Cards documentation
Token Information
Key Facts
Description
Curio Card #11 (BTC Keys) is an original 2017 Curio Cards art token with artwork by Cryptograffiti. BTC Keys opens Cryptograffiti's Cards 11-13 Bitcoin banking-logo trio. The artwork reworks the UBS logo into a pro-Bitcoin image about keys, custody, and banking imagery.
The contract uses ERC-20-style token functions with symbol CRO11, 0 decimals, and on-chain totalSupply 100000. The card token is locked, so no additional cards can be minted. Final card supply is 2000.
Heuristic Analysis
The following characteristics were detected through bytecode analysis and may not be accurate.
Spurious Dragon Era
Continued DoS protection. State trie clearing.