Category Archives: Security economics

Social-science angles of security

Authentication is machine learning

Authentication, Security economics, Security engineering

Last week, I gave a talk at the Center for Information Technology Policy at Princeton. My goal was to expand my usual research talk on passwords with broader predictions about where authentication is going. From the reaction and discussion afterwards one point I made stood out: authenticating humans is becoming a machine learning problem.

Problems with passwords are well-documented. They’re easy to guess, they can be sniffed in transit, stolen by malware, phished or leaked. This has led to loads of academic research seeking to replace passwords with something, anything, that fixes these “obvious” problems. There’s also a smaller sub-field of papers attempting to explain why passwords have survived. We’ve made the point well that network economics heavily favor passwords as the incumbent, but underestimated how effectively the risks of passwords can be managed in practice by good machine learning.

From my brief time at Google, my internship at Yahoo!, and conversations with other companies doing web authentication at scale, I’ve observed that as authentication systems develop they gradually merge with other abuse-fighting systems dealing with various forms of spam (email, account creation, link, etc.) and phishing. Authentication eventually loses its binary nature and becomes a fuzzy classification problem. Continue reading Authentication is machine learning →

Who will screen the screeners?

Legal issues, Politics, Security economics, Security engineering, Security psychology

Last time I flew through Luton airport it was a Sunday morning, and I went up to screening with a copy of the Sunday Times in my hand; it’s non-metallic after all. The guard by the portal asked me to put it in the tray with my bag and jacket, and I did so. But when the tray came out, the newspaper wasn’t there. I approached the guard and complained. He tried to dismiss me but I was politely insistent. He spoke to the lady sitting at the screen; she picked up something with a guilty look sideways at me, and a few seconds later my paper came down the rollers. As I left the screening area, there were two woman police constables, and I wondered whether I should report the attempted theft of a newspaper. As my flight was leaving in less than an hour, I walked on by. But who will screen the screeners?

This morning I once more flew through Luton, and I started to suspect it wouldn’t be the airport’s management. This time the guard took exception to the size of the clear plastic bag holding my toothpaste, mouthwash and deodorant, showing me with glee that it has half a centimetre wider than the official outline on a card he had right to hand. I should mention that I was using a Sainsbury’s freezer bag, a standard item in our kitchen which we’ve used for travel for years. No matter; the guard gleefully ordered me to buy an approved one for a pound from a slot machine placed conveniently beside the belt. (And we thought Ryanair’s threat to charge us a pound to use the loo was just a marketing gimmick.) But what sort of signal do you give to low-wage security staff if the airport merely sees security as an excuse to shake down the public? And after I got through to the lounge and tried to go online, I found that the old Openzone service (which charged by the minute) is no longer on offer; instead Luton Airport now demands five pounds for an hour’s access. So I’m writing this blog post from Amsterdam, and next time I’ll probably fly from Stansted.

Perhaps one of these days I’ll write a paper on “Why Security Usability is Hard”. Meanwhile, if anyone reading this is near Amsterdam on Monday, may I recommend the Amderdam Privacy Conference? Many interesting people will be talking about the ways in which governments bother us. (I’m talking about how the UK government is trying to nobble the Data Protection Regulation in order to undermine health privacy.)

The Perils of Smart Metering

News coverage, Politics, Security economics, Security engineering

Alex Henney and I have decided to publish a paper on smart metering that we prepared in February for the Cabinet Office and for ministers. DECC is running a smart metering project that is supposed to save energy by replacing all Britain’s gas and electricity meters with computerised ones by 2019, and to cost only £11bn. Yet the meters will be controlled by the utilities, whose interest is to maximise sales volumes, so there is no realistic prospect that the meters will save energy. What’s more, smart metering already exhibits all the classic symptoms of a failed public-sector IT project.

The paper we release today describes how, when Ed Milliband was Secretary of State, DECC cooked the books to make the project appear economically worthwhile. It then avoided the control procedures that are mandatory for large IT procurements by pretending it was not an IT project but an engineering project. We have already written on the security economics of smart meters, their technical security, the privacy aspects and why the project is failing.

We managed to secure a Cabinet Office review of the project which came up with a red traffic light – a recommendation that the project be abandoned. However DECC dug its heels in and the project appears to be going ahead. Hey, we did our best. The failure should be evident in time for the next election; just remember, you read it here first.

Password cracking, part II: when does password cracking matter?

Authentication, Security economics, Security engineering, Web security

Yesterday, I took a critical look at the difficulty of interpreting progress in password cracking. Today I’ll make a broader argument that even if we had good data to evaluate cracking efficiency, recent progress isn’t a major threat the vast majority of web passwords. Efficient and powerful cracking tools are useful in some targeted attack scenarios, but just don’t change the economics of industrial-scale attacks against web accounts. The basic mechanics of web passwords mean highly-efficient cracking doesn’t offer much benefit in untargeted attacks. Continue reading Password cracking, part II: when does password cracking matter? →

Password cracking, part I: how much has cracking improved?

Authentication, News coverage, Security economics, Web security

Password cracking has returned to the news, with a thorough Ars Technica article on the increasing potency of cracking tools and the third Crack Me If You Can contest at this year’s DEFCON. Taking a critical view, I’ll argue that it’s not clear exactly how much password cracking is improving and that the cracking community could do a much better job of measuring progress.

Password cracking can be evaluated on two nearly independent axes: power (the ability to check a large number of guesses quickly and cheaply using optimized software, GPUs, FPGAs, and so on) and efficiency (the ability to generate large lists of candidate passwords accurately ranked by real-world likelihood using sophisticated models). It’s relatively simple to measure cracking power in units of hashes evaluated per second or hashes per second per unit cost. There are details to account for, like the complexity of the hash being evaluated, but this problem is generally similar to cryptographic brute force against unknown (random) keys and power is generally increasing exponentially in tune with Moore’s law. The move to hardware-based cracking has enabled well-documented orders-of-magnitude speedups.

Cracking efficiency, by contrast, is rarely measured well. Useful data points, some of which I curated in my PhD thesis, consist of the number of guesses made against a given set of password hashes and the proportion of hashes which were cracked as a result. Ideally many such points should be reported, allowing us to plot a curve showing the marginal returns as additional guessing effort is expended. Unfortunately results are often stated in terms of the total number of hashes cracked (here are some examples). Sometimes the runtime of a cracking tool is reported, which is an improvement but conflates efficiency with power. Continue reading Password cracking, part I: how much has cracking improved? →

The rush to 'anonymised' data

Academic papers, Legal issues, News coverage, Politics, Privacy technology, Security economics, Security engineering

The Guardian has published an op-ed I wrote on the risks of anonymised medical records along with a news article on CPRD, a system that will make our medical records available for researchers from next month, albeit with the names and addresses removed.

The government has been pushing for this since last year, having appointed medical datamining enthusiast Tim Kelsey as its “transparency tsar”. There have been two consultations on how records should be anonymised, and how effective it could be; you can read our responses here and here (see also FIPR blog here). Anonymisation has long been known to be harder than it looks (and the Royal Society recently issued a authoritative report which said so). But getting civil servants to listen to X when the Prime Minister has declared for Not-X is harder still!

Despite promises that the anonymity mechanisms would be open for public scrutiny, CPRD refused a Freedom of Information request to disclose them, apparently fearing that disclosure would damage security. Yet research papers written using CPRD data will surely have to disclose how the data were manipulated. So the security mechanisms will become known, and yet researchers will become careless. I fear we can expect a lot more incidents like this one.

Call for Papers: eCrime Researchers Summit

Call for papers, Security economics, Security psychology, Web security

I have the privilege of serving as co-chair of the program committee for the Anti-Phishing Working Group’s eCrime Researchers Summit, to be held October 23-24 in Las Croabas, Puerto Rico. This has long been one of my favorite conferences to participate in, because it is held in conjunction with the APWG general meeting. This ensures that participation in the conference is evenly split between academia and industry, which leads to in-depth discussions of the latest trends in online crime. It also provides a unique audience for academic researchers to discuss their work, which can foster future collaboration.

Some of my joint work with Richard Clayton appearing at this conference has been discussed on this blog, from measuring the effectiveness of website take-down in fighting phishing to uncovering the frequent lack of cooperation between security firms. As you will see from the call for papers, the conference seeks submissions on all aspects of online crime, not just phishing. Paper submissions are due August 3, so get to work so we can meet up in Puerto Rico this October!
Continue reading Call for Papers: eCrime Researchers Summit →

Workshop on the Economics of Information Security 2012

Academic papers, Politics, Security economics, Security psychology

I’m liveblogging WEIS 2012, as I did in 2011, 2010 and 2009. The event is being held today and tomorrow at the Academy of Sciences in Berlin. We were welcomed by Nicolas Zimmer, Berlin’s permanent secretary for economics and research who mentioned the “explosive cocktail” of streetview, and of using social media for credit ratings, in he context of very different national privacy cultures; the Swedes put tax returns online and Britain has CCTV everywhere, while neither is on the agenda in Germany. Yet Germany like other countries wants the benefits of public data – and their army has set up a cyber-warfare unit. In short, cyber security is giving rise to multiple policy conflicts, and security economics research might help policymakers navigate them.

The refereed paper sessions will be blogged in comments below this post.

Debunking cybercrime myths

Academic papers, Legal issues, News coverage, Politics, Security economics, Spam

Our paper Measuring the Cost of Cybercrime sets out to debunk the scaremongering around online crime that governments and defence contractors are using to justify everything from increased surveillance to preparations for cyberwar. It will appear at the Workshop on the Economics of Information Security later this month. There’s also some press coverage.

Last year the Cabinet Office published a report by Detica claiming that cybercrime cost the UK £27bn a year. This was greeted with derision, whereupon the Ministry of Defence’s chief scientific adviser, Mark Welland, asked us whether we could come up with some more defensible numbers.

We assembled a team of experts and collated what’s known. We came up with a number of interesting conclusions. For example, we compared the direct costs of cybercrimes (the amount stolen) with the indirect costs (costs in anticipation, such as countermeasures, and costs in consequence such as paying compensation). With traditional crimes that are now classed as “cyber” as they’re done online, such as welfare fraud, the indirect costs are much less than the direct ones; while for “pure”cybercrimes that didn’t exist before (such as fake antivirus software) the indirect costs are much greater. As a striking example, the botnet behind a third of the spam in 2010 earned its owner about $2.7m while the worldwide costs of fighting spam were around $1bn.

Some of the reasons for this are already well-known; traditional crimes tend to be local, while the more modern cybercrimes tend to be global and have strong externalities. As for what should be done, our research suggests we should perhaps spend less on technical countermeasures and more on locking up the bad guys. Rather than giving most of its cybersecurity budget to GCHQ, the government should improve the police’s cybercrime and forensics capabilities, and back this up with stronger consumer protection.