related.tex

\section{Related Work}
\label{sec:related}

Our proxy rotation scheme has many of the same advantages as Tor\cite{dingledine2004tor}, such as the anonymity gained from routing traffic through many proxies. While this protocol is no replacement for Tor, we feel that our proxy rotation also has a few distinct advantages over Tor. Particularly, we think our method is advantageous with respect to evading censorship, where a powerful entity (e.g. a government) is actively blocking connections to proxies.

This is for three main reasons: primarily, we believe that our system is more resistant to shutting down nodes. Ideally, there would be many more nodes available for proxy rotation than there are exit nodes in the Tor network. We justify this by claiming the barrier for entry into our system is smaller than that for a Tor exit node. We hope that the barrier of entry to our system is low enough that it could be used by everyday people running proxies out of their garage.  Additionally, our system includes financial incentives for providing service, whereas Tor requires the goodwill of the exit nodes. Both of these should lead to a larger pool of proxies for someone choosing to use our system.

Additionally, We think it would be harder to identify and block all nodes running our proxy. It is fairly easy to identify Tor exit nodes as they are all published online\cite{tor:node} but, depending on the discovery scheme being used for the proxy rotation, it could be difficult to identify all proxies available to a client. We discussed the strengths and weaknesses of our discovery mechanisms in section \ref{sec:discovery}. 

Finally, we hope that the currency incentive will cause proxies to be more reliable. While Tor nodes try to stay online, they are free and there is less incentive for a server manager to ensure that their server stays up and operational at all times.

There is also a benefit of using proxy rotation to evade web tracking. Using Tor, your IP will look the same to a website for up to 10 minutes\cite{tor:faq}. Using the proxy rotation, however, will cause a user's IP to change over a single session, making them much harder to track. This leaves cookies and browser fingerprinting as one of the only ways to still track the user over a session. Combining this service with cookie blocking and anti-fingerprinting techniques could make it impossible for a remote server to link a user's traffic.

Conversely, there are also some drawbacks of the proxy rotation when compared to Tor. The proxy rotation system is more susceptible to man in the middle attacks, as mentioned in section \ref{sec:mitm}. Tor has the advantage of a public key infrastructure, so that clients can ensure the confidentiality and integrity of communication to each individual node, whereas our system does not maintain any such PKI. This allows Tor to chain nodes in sequence in such a way that if even one of the nodes is not malicious, then the Tor user remains anonymous. Although not currently implemented, it would be possible for proxies to provide a hash of their public key when they announce their IP and port, allowing for our system to have security properties closer to Tor's.