\chapter{Adversaries and Attacks}

While explaining the motivations behind an anonymous publishing system
like Free Haven, we enumerated a number of possible adversaries, diverse
in both goals and resources.  Several of the types of attacks that may
be employed cannot be handled merely through technology:  these include
social attacks on system security and servnet node operators, political
attacks to discourage servnet use, and government and legal attacks to
shut down nodes or arrest operators. The success of these attacks will
often depend upon the political and jurisdictional clime of servnet
nodes' physical location.  On the other hand, the success of technical
attacks -- from individuals, organizations, corporations, or national
security agencies -- is contingent upon the system's security and
robustness to attack. 

We have defined anonymity in terms of our ideal anonymous publishing
system in section \ref{chap:anon}.  In doing so, we specified a list
of protections to provide for system agents and operations.  This
section describes the various types of attacks an adversary or group of 
colluding adversaries might use against Free Haven, relating the effect
of these attacks on the level of anonymity maintained. 

There are three primary modes of attack:  on the communcations channel,
on the Free Haven servnet, and on individual files.  As the security and
anonymity of a system are only as strong as its weakest link, we have
considered all three of these, and take appropriate countermeasures for
many of these attacks.
 
\input ./fh-attacks-comm.tex

\input ./fh-attacks-infra.tex

\input ./fh-attacks-trust.tex