Have you ever thought about using a gpg key to encrypt something, but didn't due to worries that you'd eventually lose the secret key? Or maybe you did use a gpg key to encrypt something and lost the key. There are nice tools like paperkey to back up gpg keys, but they require things like printers, and a secure place to store the backups.

I feel that simple backup and restore of gpg keys (and encryption keys generally) is keeping some users from using gpg. If there was a nice automated solution for that, distributions could come preconfigured to generate encryption keys and use them for backups etc. I know this is a missing peice in the git-annex assistant, which makes it easy to generate a gpg key to encrypt your data, but can't help you back up the secret key.

So, I'm thinking about storing secret keys in the cloud. Which seems scary to me, since when I was a Debian Developer, my gpg key could have been used to compromise millions of systems. But this is not about developers, it's about users, and so trading off some security for some ease of use may be appropriate. Especially since the alternative is no security. I know that some folks back up their gpg keys in the cloud using DropBox.. We can do better.

I've thought up a design for this, called keysafe. The synopsis of how it works is:

The secret key is split into three shards, and each is uploaded to a server run by a different entity. Any two of the shards are sufficient to recover the original key. So any one server can go down and you can still recover the key.

A password is used to encrypt the key. For the servers to access your key, two of them need to collude together, and they then have to brute force the password. The design of keysafe makes brute forcing extra difficult by making it hard to know which shards belong to you.

Indeed the more people that use keysafe, the harder it becomes to brute-force anyone's key!

I could really use some additional reviews and feedback on the design by experts.

This project is being sponsored by Purism and by my Patreon supporters. By the way, I'm 15% of the way to my Patreon goal after one day!