As everyone is pointi ng out, usability is too low. A good target for usability would be TextSecure, the OTR for sms Android app (why I'm sure everyone is using).
Essentially, TextSecure works because:
1. It reverts to completely normal behavior if the recipient doesn't use TextSecure.
2. It automatically sets up keys if it recognizes the recipient uses TextSecure.
3. It never asks you for anything besides a password when you start the app the first time.
Point 2 is the difficult one for email, as is the the fact that people use email on a variety of devices, requiring syncing between computer/devices.
I would suggest emails get a X-smtg header which advertises the sending device is PGP capable, and the email client prompts the user automatically to set up key exchange. Remains syncing, which afaik isn't the hardest part.
Comments
As everyone is pointi ng out, usability is too low. A good target for usability would be TextSecure, the OTR for sms Android app (why I'm sure everyone is using).
Essentially, TextSecure works because: 1. It reverts to completely normal behavior if the recipient doesn't use TextSecure. 2. It automatically sets up keys if it recognizes the recipient uses TextSecure. 3. It never asks you for anything besides a password when you start the app the first time.
Point 2 is the difficult one for email, as is the the fact that people use email on a variety of devices, requiring syncing between computer/devices.
I would suggest emails get a X-smtg header which advertises the sending device is PGP capable, and the email client prompts the user automatically to set up key exchange. Remains syncing, which afaik isn't the hardest part.