sha256sum a8d6d8734157bbad0e30015c592275c7f75aab9e0921061c27b8259761756fde
source code
git clone

Short summaries of some of the works referenced in the bibliography.

Other places where it can be found

Berkeley EECS tech report
Ignore the "all rights reserved"; that got prepended automatically. You can do what you want with it.
eScholarship "Open Access Publications from the University of California"
It somehow ended up here as well.
Internet Archive
Backup copy of the PDF.
In order to submit the thesis I had to upload to something called proquest, which seems to be one of those typical rent-seeking parasitic publishing outfits. If you find it there, I suggest you ignore it.


  author = {David Fifield},
  title = {Threat modeling and circumvention of Internet censorship},
  school = {University of California, Berkeley},
  month = dec,
  year = 2017,
  url = {},


I'm no Donald Knuth, but if you find an error, let me know and we can work something out.

Stuff I left out

I wanted to discuss these topics, but didn't. (Mainly for a lack of time.)

Snapshots and changelog

rc2 (same as final), diff since previous
Minor edits and indexing fixes.
rc1, diff since previous
Wrote acknowledgements. Re-scanned figures for better color. Archived all URLs in references. Cleaned up index. Rewrote the abstract.
20171214, diff since previous
Edited and indexed the chapters on understanding censors, time delays, and Snowflake.
20171213, diff since previous
Edited and indexed the chapter on principles of circumvention.
20171212, diff since previous
Edited and indexed the introduction and the chapters on active probing and domain fronting. Filled in all missing figures. Moved home page from to Finalized all data sets to end at 2017-11-30.
20171201, diff since previous
Finished chapters on measurement studies / evaluation of circumvention, delays in censors' reactions, and Snowflake. All chapters are ready to read now.
20171127, diff since previous
Finished chapter on domain fronting. Added a table of meek's costs.
20171120, diff since previous
Finished Introduction. Finished chapter on active probing.
20171113, diff since previous
Moved summary of measurement papers to an appendix. Added and updated an active probing figure.
20171106, diff since previous
Finished sections on "Address blocking resistance strategies" and "Early censorship and circumvention." This covers all the topics I planned for chapter 2.
20171030, diff since previous
Finished section on "Content obfuscation strategies."
20171023, diff since previous
Began a section on "Content obfuscation strategies."
20171016, diff since previous
Drafted subsection on "Collateral damage."
20171009, diff since previous
Drafted subsection on "Spheres of influence and visibility," intro to "Principles of circumention," got started on "Collateral damage."
20171002, diff since previous
Finished first draft of the history of meek deployment, modulo some todos.
20170925, diff since previous
First draft of a long subsection on the history of meek deployment (currently Section 6.1).
20170918, diff since previous
Enumerated some in-scope and out-of-scope cases. Began working through Principles of circumvention. Roughed out references for a subsection in bridge distribution.
Hacked into rough thesis format, imported text from proposal, some editing of introduction.