Hacker Dreams Up Crypto Passport Using the Tech Behind Bitcoin

Because the World Passport is open-source software, governments are free to
use it to sign digital versions of state-issued IDs. “The real story here
is why the governments didn’t invent this sooner,” he says. “I came up with
this over a weekend in my spare time, why didn’t they? How long long has
PGP been around?”

http://www.wired.com/2014/10/world_passport