[ooni-dev] On the ethics of soliciting measurements and informed consent

royaen royaen at cs.unm.edu
Sun Dec 28 05:50:10 UTC 2014

Hi Arturo and all,

When it comes to ethics of soliciting measurements and informed consent,
I have a different take which has been my research topic over the past
years.  There are many reasons why I think that directly measuring
censorship is scary.  First of all, you need to acquire reliable vantage
points to run your measurements. Volunteering one’s machine to foreign
researchers, or operating a device on their behalf, might be viewed by
the government as espionage.  Besides, many regions, especially places
where we don’t have good infrastructure, have a limited number of
companies/volunteers (if any) that allow foreigners to rent computers
inside the country.  All the current direct approaches, such as RIPE
Atlas [1] or other distributed platforms or volunteers running Raspberry
Pis are often easy to spot and data collected from them may not be
reliable.  For example, regarding China, we showed [2] that censorship
is different in CERNET (China Education and Research Network) compared
to other ISPs.

When it comes to measuring connectivity, I believe that it is better to
involve the whole country in doing the measurements rather than
volunteers whose safety is at stake.  Therefore, I have developed
effective methods for remotely measuring Internet censorship around the
world, without requiring access to any of the machines whose
connectivity is tested to or from. These techniques are based on novel
network inference channels, a.k.a idle scans. That is, given two
arbitrary IP addresses on the Internet that meet some simple
requirements such as global IPID behaviour, our proposed technique can
discover packet drops (e.g., due to censorship) between the two remote
machines, as well as infer in which direction the packet drops are
occurring.  Here are more references to read [3,4]. Basically, for one
of the idle scans (hybrid idle scan), we only create unsolicited packets
(a bunch of SYNACK and RST segments) between two remote IPs, and look at
the changes in the global IPID variable to infer whether censorship is
happening and if so, in which direction packets are dropped.           

Back to my main point, why I am trying so hard to convince you that we
also need to use side channels and how this relates to ethics, well,
here is the story: The discussion you brought up has been discussed
heavily in academia in the past six months after two papers got rejected
from the IMC conference because of ethics. One of them was my paper [2]
after having received good reviews on the technical contribution. Here
is the link to the reviews:


I personally just got an email with above link from IMC, and because of
having had a single-entry visa, I couldn’t attend IMC or the Citizen Lab
workshop where a lot of the discussions about ethics were taking place.
The ethical issues that usually come up are two: First, using idle
scans, no consent from users is collected. Second, censors could
mistakenly assume that two machines measured by us are deliberately
communicating with each other.  This could have negative consequences if
a censor believes that a user is communicating with a sensitive or
forbidden IP address.

In response to the latter argument, it is unlikely that a censor would
come to such a conclusion as only RST segments are created from a client
inside a country to a server and only SYN/ACK segments are sent from a
server to a client inside the censoring country.  An adversary would not
witness a full TCP handshake, let alone any actual data transfer. 

One mitigation technique that I have been focusing on is to use routers
instead of end points for the side channel measurements.

If you or anyone else is interested in using these techniques, I am more
than happy to help.


[1] http://cartography.io/

[2] http://arxiv.org/abs/1410.0735



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