Quote from: gavinandresen on January 20, 2011, 09:03:15 PM

Can the attacker see all unencrypted IP traffic to/from the sender's node, or is the traffic tunneled through an anonymizing network like i2p or tor?

I am assuming that traffic between senders and nodes will be tunneled through an anonymizing network and I'm assuming that such network is secure. I'm really only trying to address the problem of transferring your coins (assumed to be tainted with your identity) to a recipient whose address you have, without allowing that recipient (or others) to learn your identity by examining the block chain. Problems of secure and anonymous communication are outside the scope.

Quote from: gavinandresen on January 20, 2011, 09:03:15 PM

Does the attacker know any of the sender's receiving bitcoin addresses?

I'm assuming not. The objective is to prevent the attacker from obtaining the sender's addresses.

Quote from: gavinandresen on January 20, 2011, 09:03:15 PM

Is the attacker willing and/or able to send 'marked bitcoins' to the sender? Lots of them?

Again I am assuming not, since the attacker doesn't know the sender's addresses.