Good evening, 

A group of students at Johns Hopkins University and I have been analyzing the circuit selection algorithm for TOR´s browser EXIT nodes. It is an exploratory project trying to discover how do the EXIT nodes are selected every time the circuit changes. 

So far, we have discovered that the time that the browser is accessed, calendar date, physical location, use of a bridge (or not), and the entry node do not change the pattern of the EXIT nodes. Moreover, than approximately 80% of all exit nodes come from 10 specific countries, even though these 10 countries only account for approximately 50% of all available exit nodes. 

All of which has led us to conclude that the selection of the EXIT nodes in the TOR browser is not random. We would like to further explore however, what are the factors that determine which relay becomes the exit node every time a circuit is changed. Is there anyone that we could speak to or that could give us further insight as to how the selection of the exit node in TOR´s circuit works?

v/r