Trustless physical cryptocurrency

A system for use of a physical digital asset comprising:

• a physical medium, the physical medium including a unique serial number and comprising one or more processors attached to the physical medium, wherein the one or more processor include an API for accessing data on the one or more processors;
• a cryptographic key generator in the one or more processors, wherein the cryptographic key generator is secured against modification, and wherein the cryptographic key generator is configured to generate a private key and corresponding public key for each of the one or more processors,
• wherein the private key is generated in the processor such that the private key is not accessible via the API;
• a communications system in the physical medium for transmitting and receiving data from a remote device;
• and
• a digital signature generator in the one or more processors, wherein the digital signature generator is secured against modification, the digital signature generator configured to receive one or more digital challenges and sign the one or more digital challenges using the private key;
• and
• a plurality of servers having a first smart contract stored thereon, wherein the smart contract is implemented by the plurality of servers and is configured to receive the one or more signed digital challenges, the first smart contract comprising information from which the public key can be derived, and the first smart contract comprises code for transferring an asset from an address on a blockchain to a user-specified destination address,
• and wherein the first smart contract comprises code to cryptographically verify that the private key associated with the public key stored in the first smart contract was used to sign the digital challenge, which causes the first smart contract to transfer ownership of the asset when presented with a valid signature.