In October, Michael Stay got a weird message on LinkedIn. A total stranger had lost access to his bitcoin private keys—and wanted Stay’s help getting his $300,000 back.
It wasn’t a total surprise that The Guy, as Stay calls him, had found the former Google security engineer. Nineteen years ago, Stay published a paper detailing a technique for breaking into encrypted zip files. The Guy had bought around $10,000 worth of bitcoin in January 2016, well before the boom. He had encrypted the private keys in a zip file and had forgotten the password. He was hoping Stay could help him break in.
In a talk at the Defcon security conference this week, Stay details the epic attempt that ensued.