I meant only slight malice here: I had intended to "expose" a few email/anon associations to highlight the problem. The problem became apparent to me when I sent pseudonymous mail to a prominent person on this list; his reply exposed his pseudonymous id at anon.penet.fi, surely without his knowledge.

I think this would be fixed by the "X-Anon-Anonymize: no" (or whatever) hack. But for reasons I have outlined in the earlier round of discussions, it can't be the default. Comments?

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an5877's message appears to be a trick, designed to collect anonymous/real address pairs. Johan Helsingius should take action against this trickster. Since he is learning other people's real addresses, perhaps it would be appropriate for his own real address to be revealed.

Now that would be a _very_ serious "bug" in the anon.penet.fi remailer (or, more accurately, in its administration); I am confident Johan Helsingius will reject this suggestion.

Definitely. I might block someone from using the server, but never (ok, "never say never") expose somebody.

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But, this does point out that these systems which automatically assign anonymous addrsses have several security flaws. Johan has already had to introduce a "password" feature to make it more difficult to send fakemail that appears to be from a particular email address through the server, thus revealing the corresponding anonymous address when it is delivered.

I think that merely masks the real problem.

It fixes *one* problem. I really appreciate suggestions for other solutions.

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These are serious problems. We need some discussion of how to avoid these simple tricks for defeating the anonymity while still having an easy-to-use system.

Any ideas? For starters, I think the default behavior of anon.penet.fi is badly broken.

There has been a lot of discussion about this, and I'm afraid it's too late to change the *default* behavior now...

But a more serious problem with anon.penet.fi and the other remailers I am aware of is the necessity that we pseudonymous clients have to rely on the integrity of their administrators to keep our pseudonyms private. In the face of social pressure, such as Xavier's, that may be asking a lot.

True. And that's why PGP-based stuff & remailer chains is the way to go for "hard" anonymity. But for posting to general newsgroups, we also need a system with working return paths. This doesn't seem possible with current remailer chain systems. Julf (admin@anon.penet.fi) P.S. In case I forgot to announce it, as you could see from the message I'm replying to, PGP stuff doesn't get stripped at anon.penet.fi anymore.....

Currently to mail to person 1234 at penet, you send mail to

anon1234@penet.fi

This mail goes out anonymously from the sender, either using an existing mail address or creating one. But if one were able to reach person 1234 also with the email address, say,

name1234@penet.fi

the behavior could be _not_ to make this posting anonymous.

To wit, the 1234 indicates that you are replying to a pseudonymous recipient, and the anon/name pair indicate whether the sender is anonymous. Thus no change in default behavior, and no new header lines.

A great idea, Eric! Thanks! Oh, a minor correction, it`s an1234, not anon1234. So in the name of symmetry the non-anonymous path should be na1234. Now we only have to fight about what the From: line in anonymous messages ought to say, an1234 or na1234? Julf