Not sure if it helps, but there's been that ``Revealing Hidden Services by their Clock Skew'' [1] 2006 paper, and some other stuff linked to from [2].
[1] http://www.cl.cam.ac.uk/~sjm217/papers/ccs06hotornot.pdf
[2] http://www.lightbluetouchpaper.org/2006/09/04/hot-or-not-rev...
Not sure if it helps, but there's been that ``Revealing Hidden Services by their Clock Skew'' [1] 2006 paper, and some other stuff linked to from [2].
[1] http://www.cl.cam.ac.uk/~sjm217/papers/ccs06hotornot.pdf
[2] http://www.lightbluetouchpaper.org/2006/09/04/hot-or-not-rev...