Forwarded message:
Date: Thu, 02 Oct 1997 23:28:10 -0400 From: "Robert A. Costner" <pooh@efga.org> Subject: Traffic Analysis
I'm curious about traffic analysis capability. While I don't know the exact figures involved, I'd say that Cracker throws away about 10% of the messages it receives. Admittedly, these are probably not encrypted messages (I don't know. Humans do not get to read the messages.) Does this make traffic analysis more difficult?
Why/how does it decide to throw them away? Does the incoming produce cover traffic even if its thrown away? Traffic analysis generaly does not look at the contents of the packets, encrypted or not is irrelevant. I suspect it would lower the estimated ratio of cover traffic if nothing gets sent out. This would in general lower the cost to analyse the traffic. I would set it up to send bogus outgoing even if the message was dropped. That way the analysis would correlate the dropped message to the outgoing and produce a cover ratio closer to the actual value. Also remember to send n+1 bogus traffic to make up for the dropped outgoing.
Or suppose Redneck sent each nym an encrypted message each day, or more often?
By 'nym' you mean each subscribed address or to each address used in the outgoing? I would say it is bad to send to subscribers. It provides non-covered traffic that identifies your subscribers specificaly (really not a threat since Mallet already has their original incoming and therefore their source address) as well as demonstrating that you are keeping long-term traffic records. The long-term records represent a clear threat to the security and stability of the remailer. If you send out this cover traffic regularly then be shure to use some mechanism to select email addresses randomly or else Mallet will get a list of your bogus addresses and begins to filter them immediately. A commercial remailer should not keep records of its use. However, I suspect that eventualy remailers will be required to keep usage records by law. ____________________________________________________________________ | | | The financial policy of the welfare state requires that there | | be no way for the owners of wealth to protect themselves. | | | | -Alan Greenspan- | | | | _____ The Armadillo Group | | ,::////;::-. Austin, Tx. USA | | /:'///// ``::>/|/ http:// www.ssz.com/ | | .', |||| `/( e\ | | -====~~mm-'`-```-mm --'- Jim Choate | | ravage@ssz.com | | 512-451-7087 | |____________________________________________________________________|