[tor-dev] Guard node security: ways forward (An update from the dev meeting)

Nicholas Hopper hopper at cs.umn.edu
Wed Feb 26 03:39:47 UTC 2014

On Tue, Feb 25, 2014 at 5:04 PM, Nicholas Hopper <hopper at cs.umn.edu> wrote:
> Another thought: we also should investigate how various thresholds
> affect the relationship between the cumulative guard weight total and
> the total exit weight.

Well, that turns out not to be a real issue: even if we set the guard
threshold to 20MBps, the total guard weight still exceeds the total
exit weight.

Here is a chart showing what fraction of total guard bandwidth is
retained as we vary the guard threshold from 0 to 10MBps:


And here's a chart showing what fraction of clients will choose the
highest (max%) and median (median%) guards as we vary the threshold
over the same range:


2MBps and 6MBps look like interesting points on the curves.

Nicholas Hopper
Associate Professor, Computer Science & Engineering, University of Minnesota
Visiting Research Director, The Tor Project

More information about the tor-dev mailing list