[freehaven-cvs] added "Obscuring messages as they leave the mix" sub...

[arma@seul.org (Roger Dingledine)]

Update of /home/freehaven/cvsroot/doc/batching-taxonomy
In directory moria.seul.org:/home/arma/work/freehaven/doc/batching-taxonomy

Modified Files:
	taxonomy.tex 
Log Message:
added 'Obscuring messages as they leave the mix' subsec



Index: taxonomy.tex
===================================================================
RCS file: /home/freehaven/cvsroot/doc/batching-taxonomy/taxonomy.tex,v
retrieving revision 1.5
retrieving revision 1.6
diff -u -d -r1.5 -r1.6
--- taxonomy.tex	7 May 2002 08:41:07 -0000	1.5
+++ taxonomy.tex	7 May 2002 13:24:33 -0000	1.6
@@ -841,7 +841,7 @@
 this tradeoff between protection from blending attacks and protection
 from verifiability.
 
-\section{Cover Traffic}
+\subsection{Cover Traffic}
 
 Another possible protection against the blending attacks is cover
 traffic. Indeed, in designing the Mixmaster system \cite{Cott94},
@@ -888,7 +888,27 @@
 with the Mixmaster cover traffic policy, a threshold mix network can
 be attacked in $\epsilon$ time (but a very large number of messages).
 
-\section{Related Work}
+\subsection{Obscuring messages as they leave the mix}
+
+Link encryption offers some limited protection against traffic
+analysis. Encrypted links between honest nodes prevent an adversary
+from recognizing even his own messages, thus making it harder to flood
+MIXes and watch where outgoing messages go. However, since the adversary
+performing the flooding attack can choose the next destination of each
+message, he may still be able to recognize his messages. At the extreme,
+he can direct all his chaff messages at the same next mix, so any other
+message will still stand out. A good link padding scheme may be able to
+further frustrate him, but much more research remains.
+
+Babel \cite{babel} introduces \emph{inter-MIX detours}, a scheme where mix
+nodes can choose to rewrap a message and send it through a few randomly
+chosen new hops --- so even the sender cannot be sure of recognizing
+his message as it leaves the mix. This approach could help complicate
+blending attacks; we leave its analysis for future work.
+
+
+\section{Related work: stop and go mixes}
+% this is fishy. the related work section has only one related work? -RRD
 \label{SG}
 
 While active attacks have been widely cited in the literature and

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