The ‘Physical Bitcoin Cold Storage Spy Coin’ is unlike any other physical crypto-coin. It is designed to hide a private key, but it has no sticker or hologram nor engraved key. Instead, it actually opens up in a way that a piece of paper or even SD memory card can be put inside the coin thus hidden in plain sight! The ‘spy coin’ comes from the historical fact that similar hollow coins were used during the Cold War to hide secret messages or even conceal drugs which an agent could use to end their life upon capture. The name ‘Cold Coin’ refers to ‘cold storage’, which is the state of crypto-currency being stored in such a way that they are ‘offline’ and impervious to hacks or accidental computer damage. The front face of the coin consists of a Bitcoin ‘B’ which is covered in gears, whereas the backside displays several gears that remind one of a mechanical watch. All 100 coins are serialized.
The coin’s categorization as ‘unfunded’ is valid since the design is intended to ‘secure’ a private key, though the lack of any security sticker means that the integrity of the stored private key (i.e., the fact that it has not been opened since being sealed) cannot be guaranteed.