[tor-reports] SponsorR February 2015 report

[George Kadianakis]

Hello,

here is the February 2015 report for SponsorR:

- We published our blog post detailing the analysis of hidden service
  statistics:
  https://blog.torproject.org/blog/some-statistics-about-onions

- We wrote code to make it easier to ask Tor for the descriptor of a
  hidden service. This will be used in the future by the HSDir health
  measurement tool:
  https://bugs.torproject.org/14845
  https://bugs.torproject.org/14847

- Started discussion on how we can make it easier for hidden services
  to announce themselves to the world. Various ideas and systems were
  suggested: https://trac.torproject.org/projects/tor/ticket/15008

- Provided feedback to the new hidden service search engine onion.city:
  https://lists.torproject.org/pipermail/tor-talk/2015-February/036894.html

- While working on statistics, we found that some of the old bandwidth
  statistics we've been gathering from relays can be used to enable a
  guard discovery attack on hidden services. We increased the
  reporting period which should help mitigate the issue:
  https://trac.torproject.org/projects/tor/ticket/13838

- More work on robustness and unit tests for our Laplace statistics
  obfuscation code: http://bugs.torproject.org/13912

- Progress in large scale simulation of hidden services using Shadow.