[ooni-talk] Iran Protests: DPI blocking of Instagram (Part 2 of research)

[Maria Xynou]

Hello,

Earlier this year we published research on the blocking of Telegram and
Instagram during the Iran protests:
https://ooni.torproject.org/post/2018-iran-protests/

OONI's Leonid has carried out further analysis of network measurements,
based on which he found that Instagram was blocked through the use of
DPI which targeted the TLS protocol during the Iran protests.

His findings are available in OONI's latest blog post:
https://ooni.torproject.org/post/2018-iran-protests-pt2/
(https://twitter.com/OpenObservatory/status/964054743143321600)

We previously thought that Instagram was blocked by means of DNS
tampering, but that turned out to be a false positive (it was in fact
blocked by DPI targeting TLS).

This is yet another case that shows the challenges in terms of
accurately identifying cases of DNS-based censorship, and distinguishing
them from false positives.

There are many other cases that may look like DNS-based censorship, but
aren't. Leonid previously published a post identifying cases of DNS
misconfiguration:
https://ooni.torproject.org/post/not-quite-network-censorship/

We therefore encourage you to please reach out if you'd like to share
knowledge/ideas/heuristics that can help improve our methodologies in
relation to identifying cases of DNS-based censorship (and
distinguishing them from false positives). Our current methodologies are
available here: https://ooni.torproject.org/nettest/web-connectivity/
(and here are some of our ideas for future tests:
https://github.com/TheTorProject/ooni-probe/issues/647).

Thank you!

~ The OONI team.

-- 
Maria Xynou
Research and Partnerships Coordinator
Open Observatory of Network Interference (OONI)
https://ooni.torproject.org/
PGP Key Fingerprint: 2DC8 AFB6 CA11 B552 1081 FBDE 2131 B3BE 70CA 417E


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