From: jim@bilbo.suite.com (Jim Miller)
Date: Mon, 31 Jan 94 17:55:27 PST
To: cypherpunks@toad.com
Subject: Re: 2-way anonymous via SASE
Message-ID: <9401312310.AA04927@bilbo.suite.com>
MIME-Version: 1.0
Content-Type: text/plain



Jon Boone writes

>   Isn't it true that no matter how many remailers you use, the full spec
>   of the return path has to be included?  And if the last remailer is 

>   keeping a log of all messages passed, then the reciever/replier need
>   only interrogate the last remailer to find out the sender's address?

At no time do any of the remailers see a "full spec of the return path",  
especially the last remailer in the chain of remailers used for the reply  
message.

You might view the SASE as a "full spec of the return path", however, only  
the receiver of the original message sees the full SASE, and the SASE is  
mostly a bunch of encrypted information nested in layers that only become  
readable as the SASE gets "unwrapped" in its trip back to the original  
sender.  Each remailer involved in the return trip sees only the layer of  
the SASE that becomes readable when it decrypts the portion of the SASE it  
received from the previous hop.  By the time reply gets to the last  
remailer (inner most layer of the SASE), the reply contains no information  
about any of the outer layers of the SASE.  All it contain is:

(Bob, D, (stuffN))Rx,  (((reply)A)B)C

(A, B, and C, indicates keys used to re-encrypt the reply.  They are not  
addresses of previous hops.)

If Bob was really unlucky, it is possible he could build an SASE using  
only remailers that are under the control of Ted.  If this happend, then  
Ted would be able to trace back to Bob.  However, "Bob" could be an  
anonymous Penet-style account and Ted would still not have learned who  
"Bob" really is.


Jim_Miller@suite.com