[Technology] E-mail encryption

In an ideal world, everyone would be able to make use of encryption in their daily life and communications. The other day, I had a mild challenge setting it up with a friend.  Basically, Apple Mail wants to handle encryption via S/MIME using certificates, which is typical of most enterprise usage.  Evolution can do that, but I'd prefer to do it via GPG/PGP using public-private keys.  The main reason is because I find that approach is more usable for personal use.  (Self-signed certificates are a bit annoying, and I find it a bit more involved to generate your own certificate.)



We finally settled on using GPG Tools for Apple Mail.  Next we had issues where I had to trust his key, which worked out, but left me wishing that GNOME had a better interface for handling keys.



Ideally to me, everyone would have a public-private key pair and have some concept of how it was used.  I'd be happy for roaming usage if they kept their private key on a tiny USB computer that you could plug into any other computer, and would have a partition the foreign computer could see, and a partition only the computer on the USB could see.  You'd drop content into the public partition and the computer would see it and sign it with the private key (which is on the private partition, so a foreign computer can't just grab it).   It could also handle data other than files copied over.  If enough software understood that there was a USB key providing a signing/encryption service, they'd have decent interfaces for requesting the USB key computer sign an e-mail or an instant message.  This (or some other solution to securely using a private key out and about) hopefully already exists. :)  (I'd imagine the USB key computer would have a button on it that you press when you approve of it signing/encrypting something.) 



Basically, I just want encryption to be easy for users and to reduce the chance of people compromising their keys.



But of course, with encrypted e-mail, there's the problem of how can you make use of webmail and its search services without allowing a third-party e-mail provider access to the plain text of messages?  I find the conveniences of Google generally worthwhile, and difficult to achieve without a large centralised infrastructure.  Hmm.