Eric S Johnson: > Hi Phillipp, > > > >> Eric, that's interesting, could you elaborate on that? > >> According to my own experience, deep packet inspection in China is still used > > > > I'm not saying China doesn't do DPI. I'm just saying that, from my own > experience living in China for the past three years, DPI doesn’t appear to be > used to inspect the contents of web pages and dynamically block undesirable > content. >
Hrm. You did actually say: "Yes-they stopped doin packet inspection in about 2008, near as I can tell." That's a bit confusing as we've seen direct evidence of DPI that results in real time *probing* of Tor bridges. We know they do DPI to do this and we know they trigger specific kinds of censorship depending on protocol. That you are not seeing content being *blocked* is not the same as the absence of DPI that is performing surveillance, protocol classification, logging and eventually, blocking. > > > I.e. it's easy to register a new domain (call it TestChinaCyberFiltering.org) > and put up onto it a handful of pages which include every possible word and > phrase which we know are problematic to the Chinese censors. Start with the > list of words which trigger censorship and surveillance in TOM Skype (the > wordlist's been repeatedly cracked by researchers at, I think, Arizona). Add > all the content which the good folks at UC-Berkeley’s China Digital Times > have detected cause immediate censorship on Weibo (China’s Twitter-like > service). This should be a total of about 400 words and phrases (almost all > only in Chinese). > > Then access those pages from within China. > > As far as I can tell, access will be unimpeded. > > It appears to me such content won't ever get blocked > unless/until it's indexed in Google. It appears that the Great Firewall is > constantly doing Google searches for undesirable content, then augmenting the > blacklist. It seems to me the actual augmentation happens only after the > "bad" content's been reviewed by a human. And although most of what we read > about involves what's blocked, there do seem to be regular reductions in > what's blocked--perhaps about once a quarter. > > But my own tests have been unscientific, i.e. not conducted > over a variety of ISPs, times, and content. It would be interesting (and not > difficult) to do this more rigorously. > If you put up such a site, I guess a lot of people here would run their tests and let us all know the results. That seems like a good way to test your theory and to test their tests. All the best, Jake _______________________________________________ liberationtech mailing list [email protected] Should you need to change your subscription options, please go to: https://mailman.stanford.edu/mailman/listinfo/liberationtech If you would like to receive a daily digest, click "yes" (once you click above) next to "would you like to receive list mail batched in a daily digest?" You will need the user name and password you receive from the list moderator in monthly reminders. You may ask for a reminder here: https://mailman.stanford.edu/mailman/listinfo/liberationtech Should you need immediate assistance, please contact the list moderator. Please don't forget to follow us on http://twitter.com/#!/Liberationtech
