Dear Ms Johnson,
Your letter of December 1st to Stephen Jolly has only this week been passed to me to deal with. I’m
afraid it contains a number of misconceptions and factual errors.
First, your letter was not correctly addressed. The University of Cambridge is a self-governing community
of scholars rather than a corporate hierarchy. Mr Jolly is responsible for the university’s front page
at www.cam.ac.uk and for some of the pages in www.admin.cam.ac.uk, but not for web pages in academic
departments. Omar Choudary is responsible for his pages at www.cl.cam.ac.uk/~osc22; I am
responsible for my pages at www.cl.cam.ac.uk/~rja14; and Steven Murdoch is responsible for his
pages at www.cl.cam.ac.uk/~sjm217 as well as being webmaster of www.lightbluetouchpaper.
org. Omar’s work was not ‘published by the university’ as you claim but by him. If you wanted him to
take his thesis offline, you should have asked him.
However, given that the material on the No-PIN attack appears on my page as well as Omar’s and
Steven’s, and given that Mr Jolly passed the matter to me to deal with, I expect that I can save us all a lot
of time by answering directly.
Second, you seem to think that we might censor a student’s thesis, which is lawful and already in the
public domain, simply because a powerful interest finds it inconvenient. This shows a deep misconception
of what universities are and how we work. Cambridge is the University of Erasmus, of Newton,
and of Darwin; censoring writings that offend the powerful is offensive to our deepest values. Thus even
though the decision to put the thesis online was Omar’s, we have no choice but to back him. That would
hold even if we did not agree with the material! Accordingly I have authorised the thesis to be issued as
a Computer Laboratory Technical Report. This will make it easier for people to find and to cite, and will
ensure that its presence on our web site is permanent.
Third, Omar’s thesis does not contain any new information on the No-PIN vulnerability. That was
discovered by Steven Murdoch, Saar Drimer and me in 2009, disclosed responsibly to the industry,
and published in February this year. It is not expected that an MPhil thesis contain novel scientific
work. Omar’s work describes and publishes the design of a platform for investigating and testing EMV
generally and its primary uses are defensive: first, to enable customers to monitor transactions if they
wish, and second to enable merchants and banks to test their own systems to see whether their system
suppliers are telling the truth about security. I note you have announced the purchase of a terminal
communications monitor from Barnes International. Omar’s device, which I understand he also offers
for sale to industry firms in a private capacity, is for just that – monitoring terminal communications.
Fourth, he did not make available the source code for the No-PIN attack. Steven Murdoch, Saar Drimer
and I did that in our research paper earlier this year. Omar did not include that code in his thesis.
Fifth, you say ‘Concern was expressed to us by the police that the student was allowed to falsify a
transaction in a shop in Cambridge without first warning the merchant’. I fail to understand the basis
for this. The banks in France had claimed (as you did) that their systems were secure; a French TV
programme wished to discredit this claim (as Newsnight discredited yours); and I understand that Omar
did a No-PIN transaction on the card of a French journalist with the journalist’s consent and on camera.
At no time was there any intent to commit fraud; the journalist’s account was debited in due course in
accordance with his mandate and the merchant was paid. It is perfectly clear that no transaction was
falsified in any material sense. I would not consider such an experiment to require a reference to our
ethics committee. By that time the Newsnight programme had appeared and the No-PIN attack was
entirely in the public domain. The French television programme was clearly in the public interest, as it
made it more difficult for banks in France to defraud their customers by claiming that their systems were
secure when they were not.
You complain that our work may undermine public confidence in the payments system. What will
support public confidence in the payments system is evidence that the banks are frank and honest in
admitting its weaknesses when they are exposed, and diligent in effecting the necessary remedies. Your
letter shows that, instead, your member banks do their lamentable best to deprecate the work of those
outside their cosy club, and indeed to censor it.
Nonetheless, I am delighted to note your firm statement that the attack will no longer work and pleased
that the industry has been finally been able to deal with this security issue, albeit some considerable time
after the original disclosure back in 2009.