Fix minor typos and add a cite for Privoxy

@Misc{anonymizer,

  key =          {anonymizer},

  title =        {The {Anonymizer}},

  note =         {\url{http://www.anonymizer.com}}

  note =         {\url{http://www.anonymizer.com/}}

}

@Misc{privoxy,

  key =          {privoxy},

  title =        {{Privoxy}},

  note =         {\url{http://www.privoxy.org/}}

}

@Misc{anonnet,

\cite{socks4,socks5} proxy interface, allowing us to support most TCP-based

programs without modification.  This design change allows Tor to

use the filtering features of privacy-enhancing

application-level proxies such as Privoxy without having to

application-level proxies such as Privoxy \cite{privoxy} without having to

incorporate those features itself.

\item \textbf{Many TCP streams can share one circuit:} The original

Tor belongs to the second category: \emph{low-latency} designs that attempt

to anonymize interactive network traffic.  Because these protocols typically

involve a large number of packets that much be delivered quickly, it is

involve a large number of packets that must be delivered quickly, it is

difficult for them to prevent an attacker who can eavesdrop both ends of the

interactive communication from points from correlating the timing and volume

of traffic entering the anonymity network with traffic leaving it.  These

appearance of packets to hide the path; rather they try to prevent an

intermediary from knowing when whether it is talking to an ultimate

initiator, or just another intermediary.  Crowds uses no public-key

encryption encryption, but the responder and all data are visible to all

encryption, but the responder and all data are visible to all

nodes on the path so that anonymity of connection initiator depends on

filtering all identifying information from the data stream. Crowds only

supports HTTP traffic.

  % the enclave-firewall model? -RD

  % I don't think we should. -NM

\item[No protocol normalization:] Tor does not provide \emph{protocol

  normalization} Privoxy or the Anonymizer.  In order to make clients

  normalization} like Privoxy or the Anonymizer.  In order to make clients

  indistinguishable when they complex and variable protocols such as HTTP,

  Tor must be layered with a filtering proxy such as Privoxy to hide

  differences between clients, expunge protocol features that leak identity,