[foobarqux]

That's not forward secrecy. Usenet with encryption is not forward secret either.

> If you're worried by such an attacker [...]

Uh, shouldn't everyone be at this point?

> you can just create a new identity for each message

Key exchange and management is hard. That's why you try not to do it often. You could claim PGP e-mail was forward secret: All you need to do is use a new private key every time.

[berdario]

I know, that's why I wrote "forward secrecy is helped", it's not something that you get out of the box with bitmessage

moreover, since the keypair and the BM identity is one-and-the-same the key exchange and management comes for free, once you got the first message sent to your recipient... changing identity is much easier than creating a new gpg keypair and sending it to the other guy, and on top of that you'll get some added anonimity