The phenomenon of disappearing Bitcoins

Unlike banks, Bitcoins are unregulated. If an owner dies without passing on their password (called a private key), their Bitcoins expire with them. They’ll remain in the ether, visible but unspendable. Nobody to help.

You could imagine them eventually falling prey to brute force attacks – someone guessing key after key until they stumble upon the correct one. But that’s where Bitcoin’s formidable security becomes a problem.

Security expert Bruce Schneier once ruled out an attempt to crack a 256-bit key, of the type used by Bitcoin, by referring to the laws of physics: such is the magnitude of the problem. Even an impracticably large computer consuming all the energy outputted by the sun couldn’t count the number of possible combinations in several decades.

His mind-bending conclusion was that such an attack “will be infeasible until computers are built from something other than matter and occupy something other than space.”… CONTINUE