But Andresen isn’t your typical bitcoin user. He’s the chief scientist at the Bitcoin Foundation and one of the primary authors of the software that runs bitcoin’s peer-to-peer network, and even before his bitcoins were stolen, he had an idea about how to make this kind of theft more difficult. He calls it P2SH — short for “pay-to-script hash” — and it’s basically a hack of the protocol that drives the digital currency. It lets you keep your bitcoins safe even if your primary private key is stolen. You see, bitcoin’s other great strength is that it’s open source software. It can be hacked and extended. And that’s what Andresen has done.