> If you are not able to manage your keys, which includes a simple unencrypted key-backup, you are doomed, even with a pretty interface. Too many hackers equat

> If you are not able to manage your keys, which includes a simple unencrypted key-backup, you are doomed, even with a pretty interface. Too many hackers equate "good user experience" with "pretty interface". It's a mistake. A good user experience really would abstract the complexity out of key management, without compromising security. This is one of the most important outstanding problems you could solve: find a way to leverage people's existing meatspace notions of trust in a concrete way to build a robust PKI. If you can make the whole process by the side-effect of a game, so much the better. And give them keys that are physical things -- they know how to protect valuable physical things, and they know who they can trust with a backup copy. None of this is easy, but it's vitally important.