Category Archives: Banking security

The security of the banking system, as well as hardware and software commonly used in such installations

A Merry Christmas to all Bankers

Academic papers, Banking security, Internet censorship, Legal issues, News coverage, Politics, Security engineering

The bankers’ trade association has written to Cambridge University asking for the MPhil thesis of one of our research students, Omar Choudary, to be taken offline. They complain it contains too much detail of our No-PIN attack on Chip-and-PIN and thus “breaches the boundary of responsible disclosure”; they also complain about Omar’s post on the subject to this blog.

Needless to say, we’re not very impressed by this, and I made this clear in my response to the bankers. (I am embarrassed to see I accidentally left Mike Bond off the list of authors of the No-PIN vulnerability. Sorry, Mike!) There is one piece of Christmas cheer, though: the No-PIN attack no longer works against Barclays’ cards at a Barclays merchant. So at least they’ve started to fix the bug – even if it’s taken them a year. We’ll check and report on other banks later.

The bankers also fret that “future research, which may potentially be more damaging, may also be published in this level of detail”. Indeed. Omar is one of my coauthors on a new Chip-and-PIN paper that’s been accepted for Financial Cryptography 2011. So here is our Christmas present to the bankers: it means you all have to come to this conference to hear what we have to say!

Financial Cryptography and Data Security 2011 — Call for Participation

Academic papers, Banking security, Call for papers, Security engineering

Financial Cryptography and Data Security (FC 2011)
Bay Gardens Beach Resort, St. Lucia
February 28 — March 4, 2011

Financial Cryptography and Data Security is a major international forum for research, advanced development, education, exploration, and debate regarding information assurance, with a specific focus on commercial contexts. The conference covers all aspects of securing transactions and systems.

NB: Discounted hotel rate is available only until December 30, 2010

Topics include:

Anonymity and Privacy, Auctions and Audits, Authentication and Identification, Backup Authentication, Biometrics, Certification and Authorization, Cloud Computing Security, Commercial Cryptographic Applications, Transactions and Contracts, Data Outsourcing Security, Digital Cash and Payment Systems, Digital Incentive and Loyalty Systems, Digital Rights Management, Fraud Detection, Game Theoretic Approaches to Security, Identity Theft, Spam, Phishing and Social Engineering, Infrastructure Design, Legal and Regulatory Issues, Management and Operations, Microfinance and Micropayments, Mobile Internet Device Security, Monitoring, Reputation Systems, RFID-Based and Contactless Payment Systems, Risk Assessment and Management, Secure Banking and Financial Web Services, Securing Emerging Computational Paradigms, Security and Risk Perceptions and Judgments, Security Economics, Smartcards, Secure Tokens and Hardware, Trust Management, Underground-Market Economics, Usability, Virtual Economies, Voting Systems

Important Dates

Hotel room reduced rate cut-off: December 30, 2010
Reduced registration rate cut-off: January 21, 2011

Please send any questions to fc11general@ifca.ai

Continue reading Financial Cryptography and Data Security 2011 — Call for Participation →

The Smart Card Detective: a hand-held EMV interceptor

Banking security, Hardware & signals, Protocols, Security engineering

During my MPhil within the Computer Lab (supervised by Markus Kuhn) I developed a card-sized device (named Smart Card Detective – in short SCD) that can monitor Chip and PIN transactions. The main goal of the SCD was to offer a trusted display for anyone using credit cards, to avoid scams such as tampered terminals which show an amount on their screen but debit the card another (see this paper by Saar Drimer and Steven Murdoch). However, the final result is a more general device, which can be used to analyse and modify any part of an EMV (protocol used by Chip and PIN cards) transaction.

Using the SCD we have successfully shown how the relay attack can be mitigated by showing the real amount on the trusted display. Even more, we have tested the No PIN vulnerability (see the paper by Murdoch et al.) with the SCD. A reportage on this has been shown on Canal+ (video now available here).

After the “Chip and PIN is broken” paper was published some contra arguments referred to the difficulty of setting up the attack. The SCD can also show that such assumptions are many times incorrect.

More details on the SCD are on my MPhil thesis available here. Also important, the software is open source and along with the hardware schematics can be found in the project’s page. The aim of this is to make the SCD a useful tool for EMV research, so that other problems can be found and fixed.

Thanks to Saar Drimer, Mike Bond, Steven Murdoch and Sergei Skorobogatov for the help in this project. Also thanks to Frank Stajano and Ross Anderson for suggestions on the project.

An old scam still works

Academic papers, Banking security, Legal issues, News coverage

In the very first paper I wrote on ATM fraud, Why Cryptosystems Fail, the very first example I gave of a fraud came from the case R v Moon at Hastings Crown Court in February 1992. Mr Moon was a teller at the TSB who noticed that address changes weren’t audited. He found a customer with over £10,000 in her account, changed her address to his, issued a card and pin, and changed the address back. He looted her account and when she complained, she wasn’t believed.

It’s still happening, most recently to a customer of the Abbey. Bank insider issues extra card, steals money, customer blamed – after all, chip and pin is infallible, isn’t it? Expecting banks to keep decent logs might be too much; and I supppose it’s way too much to expect bank fraud staff to read the research literature on their subject.

IEEE best paper award

Academic papers, Awards, Banking security, News coverage, Protocols, Security engineering

Steven Murdoch, Saar Drimer, Mike Bond and I have just won the IEEE Security and Privacy Symposium’s Best Practical Paper award for our paper Chip and PIN is Broken. This was an unexpected pleasure, given the very strong competition this year (especially from this paper). We won this award once before, in 2008, for a paper on a similar topic.

Ross, Mike, Saar, Steven (photo by Joseph Bonneau)

Update (2010-05-28): The photo now includes the full team (original version)

PINs and the burden on customers

Authentication, Banking security

A survey by the Consumers’ Association shows that 10% of cardholders write down or share their PIN. This high proportion surely raises serious doubt about whether it’s fair for banks to claim that such people are “grossly negligent” even if the PIN is well disguised (for example, as part of a phone number in an address book with hundreds of other numbers). And if banks don’t want disabled people to share PINs with carers, they ought to come up with an alternative, or be held to account under disability discrimination laws.

Interestingly, Mark Bowerman (PR for the banks) says in this article that customers should not use the same PIN for multiple cards. We heard him on radio saying exactly the opposite a few years ago. Now he tells people to change PINs to something easy to remember (and easier for criminals to guess).

By giving customers contradictory and impractical advice, the banks are placing an unmeetable burden on them.

The banks also frequently give advice that is simply wrong. Look, for example, at this video by Barclays showing how to enter your PIN at a merchant terminal!

How to get money back from a bank

Banking security, Legal issues, Politics, Security economics

I’ve written enough over the years about people who tried and failed to get money back from banks after seeing transactions on their accounts that they did not recognise. Now I’ve had to go through the process myself.

I got a refund from the NatWest after a dodgy debit appeared on the credit card my wife uses. The bank’s dispute resolution mechanism turned out to be unserviceable, but we got the money back promptly when we sued them in the small claims court. The story is, I believe, an instructive one for people interested in bank security or payment systems regulation.

Continue reading How to get money back from a bank →

Cambridge Science Festival: Science research now!

Banking security, Seminars

The annual Cambridge Science Festival is running during 8–21 March, where there are over 150 talks, demonstrations and other events, open to the public.

On Saturday 13th March (16:00–16:45), I will be talking about my recent work on Chip and PIN security. In the same session, there will also be presentations from Leila Luheshi on Alzheimer’s Disease, and Adrian Owen discussing his research on the awareness of brain-damage victims. The session will be hosted by The Naked Scientists.

For more details, see the event page — science research now!. The talk is free and no booking is required. It will be held in the Cockcroft Lecture Theatre.

Reliability of Chip & PIN evidence in banking disputes

Academic papers, Banking security, Legal issues

It has now been two weeks since we published our paper “Chip and PIN is broken”. Here, we presented the no-PIN attack, which allows criminals to use a stolen Chip and PIN card, without having to know its PIN. The paper has triggered a considerable amount of discussion, on Light Blue Touchpaper, Finextra, and elsewhere.

One of the topics which has come up is the effect of the no-PIN vulnerability on the consideration of evidence in disputed card transactions. Importantly, we showed that a merchant till-receipt which shows “PIN verified” cannot be relied upon, because this message will appear should the attack we presented be executed, even though the wrong PIN was entered.

On this point, the spokesperson for the banking trade body, the UK Cards Association (formerly known as APACS) stated:

“Finally the issuer would not review a suspected fraud involving a PIN and make a decision based on the customer’s paper receipt stating that the transaction was “PIN verified”, as suggested by Cambridge.”

Unfortunately card issuers do precisely this, as shown in a recent dispute over £9,500 worth of point-of-sale transactions, between American Express and a customer. In their letter to the Financial Ombudsman Service, American Express presented the till receipt as the sole evidence that the PIN was correctly entered:

“We also requested at the time of this claim, supporting documents from [the merchant] and were provided a copy of the till receipts confirming these charges were verified with the PIN.”

Requests to American Express for the audit logs that include the CVR (card verification results), which would have shown whether or not the no-PIN attack had been used, were denied. The ombudsman nevertheless decided against the customer.

The issue of evidence in disputed transaction cases is complex, and wider than questions raised by just the no-PIN attack. To help bring some clarity, I wrote an article, “Reliability of Chip & PIN evidence in banking disputes”, for the 2009 issue of the Digital Evidence and Electronic Signature Law Review, a law journal. This article was written for a legal audience, but would also be suitable for other non-technical readers. It is now available online (PDF 221 kB).

In this article, I give an introduction to payment card security, both Chip & PIN and its predecessors. Then, it includes a high-level description of the EMV protocol which underlies Chip & PIN, with an emphasis on the evidence it generates. A summary of various payment card security vulnerabilities is given, and how their exploitation might be detected. Finally, I discuss methods for collecting and analyzing evidence, along with difficulties currently faced by customers disputing transactions.

Chip and PIN is broken

Academic papers, Banking security, Legal issues, News coverage, Politics

There should be a 9-minute film on Newsnight tonight (10:30pm, BBC Two) showing some research by Steven Murdoch, Saar Drimer, Mike Bond and me. We demonstrate a middleperson attack on EMV which lets criminals use stolen chip and PIN cards without knowing the PIN.

Our technical paper Chip and PIN is Broken explains how. It has been causing quite a stir as it has circulated the banking industry privately for over 2 months, and it has been accepted for the IEEE Symposium on Security and Privacy, the top conference in computer security. (See also our FAQ and the press release.)

The flaw is that when you put a card into a terminal, a negotiation takes place about how the cardholder should be authenticated: using a PIN, using a signature or not at all. This particular subprotocol is not authenticated, so you can trick the card into thinking it’s doing a chip-and-signature transaction while the terminal thinks it’s chip-and-PIN. The upshot is that you can buy stuff using a stolen card and a PIN of 0000 (or anything you want). We did so, on camera, using various journalists’ cards. The transactions went through fine and the receipts say “Verified by PIN”.
Continue reading Chip and PIN is broken →