"Subway" remailers
Need ideas/comments: I have been modeling remailer scenarios using IBM VM/ESA virtual machines. After fwaffing a bit, looking at the traffic analysis concern, and taking note of some of the probability work posted recently, I thought I might throw this idea out for a sanity check: "Subway" remailers. "Subway" remailers would exchange identical sized "containers", much like a subway at semi-regular pulses or intervals. It would require a ring of remailers large enough (yeah, I know) to make traffic analysis of entrance and exit points difficult and/or expensive. Each container would contain either fixed or variable slots for multiple messages. Containers could be full, partially full, or even empty. (there would probably have to be a max message size) Subway remailers would be able to carry a message to a designated "last" remailer or to deliver blindly to a "last" remailer of random choosing. Messages may or may not change containers at the various stations/remailers. It could be randomized. Possible header scripts: X-Subway-Script: Ride 2; Latent: 03:30; Ride 3; Deliver; or many other possibilities. The whole container would be encrypted to the next remailer, giving the next remailer the same access to exchange passengers or to make them wait in a latent state. The quirkier matters on this are how to handle PGP so that nothing is compromised and for how the remailers to identify each other as "friendly and operational" so the subway system does not have a traffic jam. Crypto comments please. ------------------------------------------------------------------ P M Dierking |
The idea is a very good one, its usually called "link encryption." The idea is to make it difficult to tell when someone is using a line by filling that line with random noise that looks like encrypted data. Making a remailer do this is an interesting idea. Perhaps a subscription facility, so you can ask a remailer to send you X messages per day, with X higher than your anticipated traffic? Alternately, you could get roughly X messages per day, so a small overflow wouldn't show up at once. Adam | "Subway" remailers would exchange identical sized "containers", much | like a subway at semi-regular pulses or intervals. It would require | a ring of remailers large enough (yeah, I know) to make traffic analysis | of entrance and exit points difficult and/or expensive. -- "It is seldom that liberty of any kind is lost all at once." -Hume
participants (2)
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Adam Shostack -
xpat@vm1.spcs.umn.edu