Invisiblog (24 Apr 2003)

Imperial shifted fileservers yesterday, which is why IV was giving access denied errors. In fact, due to the wonders of NFS, it may be down for a while longer as stale filehandles are removed.

Invisiblog is a mixmaster based blogging system designed for totally anonymous blogging. This kind of stuff really appeals to me in a "yay freedom!" kind of way. If I had the hosting that could take the traffic and legal problems I would have done this sort of thing a while back - it's good that someone else has.

But I would wonder exactly how anonymous they are. I have all the usual faith in Mixmaster and they seem like sensible people so I'm assuming no stupid screwups. But it's really hard to avoid slow intersection attacks.

(Aside for people who don't know about intersection attacks: Assume I said "I was on the I10, going to work when the sun got in my eyes and I hit the central barrier, leaving a bright red mark on the barrier and a big dent in my door". From that we can say that the writer a is a member of the intersection of a) the set of people who live in LA (high chance) b) the set of people who are driving east in the morning (the sun got in their eyes) c) the set of people who have a dent in their left door / paid a garage for repairs sometime soon after d) the set of people with red cars)

Even your style of writing can give a fair amount away. As a quick test I wrote a short python script to find the mean and std dev of the numbers of 4 charactors (';', ',', '-', '?') in each sentence and the length of each sentence.

Given some sample data. (Where would you go to find long, rambling prose? The Freenet mailing list archives of course! ) Here are the results for 3 people:

Ian: [(0.0, 0.0), (1.173, 1.028), (0.464, 0.677), (0.042, 0.204), (110.536, 52.722)]
Oskar: [(0.0, 0.0), (0.675, 0.812), (0.253, 0.464), (0.12, 0.328), (97.409, 60.337)]
Matt: [(0.024, 0.153), (0.689, 0.905), (0.262, 0.642), (0.19, 0.395), (77.963, 59.192)]

(I would have included Scott, but he doesn't say enough!)

There are a fair number of differences even in this trivial test. If they use semi-colons - it's Matt. Lots of commas? Ian.

So, given someone who seems to know a lot about Freenet I think I could narrow it down a fair amount using this very simple test by analysing the list archives. (assuming that they post to the list)

The lesson is: be very careful