How to herd cats: tie a small bright object to a string; place it in the peripheral vision of the cat; and then pull it around a corner out of sight.

Ben Laurie has been trying to entice me to pounce on tor. … I pounced yesterday morning.

Tor helps to frustrate the man in the middle’s attempt to monitor your internet usage patterns. For example.

Pretend to be the man watching my internet usage. You see me send mail to Mary, and then visit a travel site, and finally send mail to Tom. What do you think I’m doing? Notice that all those connections are unencrypted so you can probably know a lot more than just that pattern of usage.

Tor frustrates that kind of model building by mixing your traffic up with that of other tor users, partially encrypting things, and some other tricks. Mixing your traffic with a crowd of other users makes observing your patterns much harder. That’s done by bouncing traffice around the internet thru tor router nodes run by volunteers.

For example here’s my email to Mary intermediated by the Tor system. I send it to proxy on my machine; it’s encrypted, bounced around the Tor network a bit and then unencrypted and passed to Mary.

On my Mac this was really easy to set up; well in the usual geek sense of easy: download; build; install; cleanup; run it.


curl -o f.tgz http://freehaven.net/tor/dist/tor-0.0.8pre3.tar.gz
tar zxt f.tgz
cd tor*
./configure && make && sudo make install
Password: ...
F=`pwd` ; cd .. ; rm -rf $F f.tgz
tor


But you should proably follow the directions.

Then you need to adjust your Network Preferences to use it. Each interface has settings for proxies; you need to set the ‘Socks Proxy’ to use 127.0.0.1 (i.e. your own machine) and port 9050. I setup a “locations” in the network preferences for that.

I had having trouble with reaching things on my local private network; until the nice folks in the tor community tapped me with the clue stick and pointed out that you can write domain names to not route thru the proxy – it’s right there on the same page where you turn on the proxy – duh. I’ve also had some problems with client software that seem to disregard the network preference settings for proxies.