[tor-talk] What is preventing Bridge Enumeration?

[Philipp Winter]

On Wed, Feb 15, 2017 at 02:32:32PM +0100, BVpTuvb AVMV wrote:
> What is preventing an attacker to start up a few mid-nodes and
> enumerating all IPs and substracting those from the list of publicly
> known entry-nodes to get a list of (all) unlisted bridges?

That is indeed a problem.  Section III.D of the following paper talks
about the issue in greater detail:
<https://censorbib.nymity.ch/pdf/Ling2012a.pdf>