On top of that, while I wouldn't rely on this cryptographically, the relationship is one-way. Gravatar links email addresses to gravatar images, but it's not intended to link in the other direction, so the same is true for any information stored in the gravatar.
You can use my system to reply with encrypted text to a comment on a blog post without knowing the email address of the person you're replying to, only their gravatar image.
Get full disk encryption and be happy.
Full disk encryption and per-user encryption are good steps. But an accidental backup of Pidgin will still reveal passwords that would be safe if they bothered to use platform specific APIs for such storage.
The logs of the conversation can be protected in the same way, so I'm not sure what that has to do with anything. (Although you might wish to keep logs as plaintext, to facilitate backups, if you're not backing up the user's keychain info.)
> No. The Pidgin developers are generally open to, and would encourage integration with keyrings (KeyringSupport).
and then goes on to state that this is difficult to do, since Pidgin runs on so many different platforms, then stating again that they will happily accept such patches.
However, I find it understandable, that the devs don’t go out of their way to support use-cases they don’t feel necessary to support. On their systems, they trust the filesystem and are happy with that, if others don’t have that level of trust in their computer, that’s fine, but not necessarily their problem.
My point about the logfiles was that to store these in the keyring (rather than a key to the encrypted files) would probably annoy the keyring somewhat (at least the poorer implementations thereof), given that it is intended for use with few-byte passwords and not multi-megabyte logfiles.
As far as logs, do what everyone does when you can only store a bit of material: Store your bulk encryption key there.