Does there exist any sort of browser extension that will, if both I and Otherperson have it installed, do this:
I type an email to Otherperson. The extension automatically grabs Otherperson's public key from a server or my keyring and encrypts the message, surrounding it with tags like [Message Encrypted Using SuchAndSuchExtension]. Otherperson receives the message, their copy of the extension sees those tags, and it is automatically decrypted.
The extension I want needs to do this automatically and silently, without
throwing up any garish pop-ups like it thinks it's the FBIses and the cyber-hacksers have hacksed all the nodes to steal all the Presidents. There should be at most
a subdued little inline note at the top of the textbox, saying "This message will be encrypted with Sane Normal Encryption, the sane and normal encryption extension that was not designed by an unusually stupid twelve-year-old boy."
Does this exist? If not, why not? I mean, what is this, 199-fucking-2?
Other desirable features:
* It would be excellent if this didn't work merely in email: like, you could set it up to automatically encrypt and decrypt Facebook messages! Or you could encrypt bits of blog posts so that only specific people could read them. In this case, it would be best if the encrypted text were hidden, so people for whom it's not intended don't have their screens cluttered up with a bunch encrypted prattle. Something vaguely like this, I guess?:
a href="http://sanenormalencryption.com" title="[Message Encrypted Using SuchAndSuchExtension]hkjdfhaksjdhfksahdfsk[/Message Encrypted Using SuchAndSuchExtension]">[Message Encrypted Using SuchAndSuchExtension]<
* Inline encryption and decryption of attachments would be preferred.
* It would be good if step one also saved a copy encrypted with my own public key in some fashion - by sending a second copy of the email to oneself, by saving to local memory somewhere, or by saving to a specified cloud destination.