[tor-bugs] #20348 [Metrics/Censorship analysis]: Kazakhstan blocking of vanilla Tor and obfs4 by Allot Communications hardware, 2016-06
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Tue Jun 6 00:35:34 UTC 2017
#20348: Kazakhstan blocking of vanilla Tor and obfs4 by Allot Communications
hardware, 2016-06
-----------------------------------------+-------------------------
Reporter: dcf | Owner:
Type: project | Status: closed
Priority: Medium | Milestone:
Component: Metrics/Censorship analysis | Version:
Severity: Normal | Resolution: invalid
Keywords: censorship block kz | Actual Points:
Parent ID: | Points:
Reviewer: | Sponsor:
-----------------------------------------+-------------------------
Comment (by dcf):
Using the data from comment:192, here is a visualization of bridge
bootstrapping from US and KZ over the past few months. For each bridge,
there is one connection attempt per hour. The dots on the graph show the
maximum bootstrap percentage reached in each attempt (10% = no
connectivity, 100% = complete bootstrapping, percentages in the middle
mean some connectivity but bootstrap didn't complete).
When the blue dot and the red dot are in the same place, it means that
there was no extra blocking in KZ. When the blue dot is lower than the red
dot, it means there was some additional blocking in KZ.
There are three gaps in the KZ data where there are no measurements: Dec
28 to January 12, April 8 to April 26, and after May 2.
[[Image(kz-data-20170605.png)]]
This table shows the average maximum bootstrap percentage reached during
the times when ''both'' the US and KZ sites were taking measurements
(i.e., excluding the gaps mentioned above). What we see from this is that
the majority of measured bridges are not in fact blocked. The only bridges
where the KZ rate is lower than the US rate are ndnop3, ndnop5, GreenBelt,
Lisbeth, and NX01. Bridges that were added more recently, or were never
used, are not more blocked in KZ. This makes me think that the firewall's
blocking is based more on a blacklist than on dynamic timing detection.
{{{#!html
<table class="wiki">
<tr><th>bridge</th><th>US average bootstrap %</th><th>KZ average bootstrap
%</th></tr>
<tr><td>ndnop3</td><td align=right style="background:
#EBCAC9">63.33%</td><td align=right style="background:
#DD918A">20.68%</td></tr>
<tr><td>ndnop5</td><td align=right style="background:
#ECCDCC">65.75%</td><td align=right style="background:
#DD9189">20.53%</td></tr>
<tr><td>GreenBelt:80</td><td align=right style="background:
#EAC7C6">61.21%</td><td align=right style="background:
#D9837A">10.21%</td></tr>
<tr><td>GreenBelt:443</td><td align=right style="background:
#EAC7C6">61.21%</td><td align=right style="background:
#DD918A">21.21%</td></tr>
<tr><td>GreenBelt:5881</td><td align=right style="background:
#EAC7C6">61.24%</td><td align=right style="background:
#DD918A">20.86%</td></tr>
<tr><td>Lisbeth</td><td align=right style="background:
#F7FAFE">99.32%</td><td align=right style="background:
#E4AEAA">42.84%</td></tr>
<tr><td>NX01:443</td><td align=right style="background:
#F7FAFE">99.58%</td><td align=right style="background:
#E4AFAB">43.50%</td></tr>
<tr><td>cymrubridge30:80</td><td align=right style="background:
#F7FBFF">100.00%</td><td align=right style="background:
#F7FAFD">98.93%</td></tr>
<tr><td>cymrubridge31:80</td><td align=right style="background:
#F7FBFF">100.00%</td><td align=right style="background:
#F7FAFD">98.94%</td></tr>
<tr><td>cymrubridge32:80</td><td align=right style="background:
#F7FBFF">100.00%</td><td align=right style="background:
#F7FAFE">99.48%</td></tr>
<tr><td>cymrubridge33:80</td><td align=right style="background:
#F6F9FD">98.38%</td><td align=right style="background:
#F7FAFD">98.97%</td></tr>
<tr><td>frosty:80</td><td align=right style="background:
#F7FBFF">100.00%</td><td align=right style="background:
#F7FAFE">99.04%</td></tr>
<tr><td>frosty:40035</td><td align=right style="background:
#F7FBFF">100.00%</td><td align=right style="background:
#F6F9FD">98.42%</td></tr>
<tr><td>camille:80</td><td align=right style="background:
#F7FBFF">100.00%</td><td align=right style="background:
#F7FAFE">99.26%</td></tr>
<tr><td>camille:42779</td><td align=right style="background:
#F7FBFF">100.00%</td><td align=right style="background:
#F7F9FD">98.68%</td></tr>
<tr><td>dragon:80</td><td align=right style="background:
#F7FBFF">100.00%</td><td align=right style="background:
#F7FAFE">99.26%</td></tr>
<tr><td>dragon:38224</td><td align=right style="background:
#F7FBFF">100.00%</td><td align=right style="background:
#F7F9FD">98.68%</td></tr>
<tr><td>dimple:80</td><td align=right style="background:
#F7FBFF">100.00%</td><td align=right style="background:
#F7FAFD">98.97%</td></tr>
<tr><td>dimple:44769</td><td align=right style="background:
#F7FBFF">100.00%</td><td align=right style="background:
#F7FBFE">99.63%</td></tr>
<tr><td>unused-cypherpunkskludge</td><td align=right style="background:
#F7FAFE">99.61%</td><td align=right style="background:
#F6F8FC">97.70%</td></tr>
<tr><td>unused-iat0</td><td align=right style="background:
#F7FAFE">99.62%</td><td align=right style="background:
#F6F5F8">95.60%</td></tr>
<tr><td>unused-iat1</td><td align=right style="background:
#F7FAFE">99.61%</td><td align=right style="background:
#F6F9FD">98.31%</td></tr>
<tr><td>unused-iat2</td><td align=right style="background:
#E6B4B1">47.37%</td><td align=right style="background:
#E6B5B2">47.92%</td></tr>
</table>
}}}
--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/20348#comment:193>
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