Category Archives: Security economics

Social-science angles of security

Trusted Computing 2.0

There seems to be an attempt to revive the “Trusted Computing” agenda. The vehicle this time is UEFI which sets the standards for the PC BIOS. Proposed changes to the UEFI firmware spec would enable (in fact require) next-generation PC firmware to only boot an image signed by a keychain rooted in keys built into the PC. I hear that Microsoft (and others) are pushing for this to be mandatory, so that it cannot be disabled by the user, and it would be required for OS badging. There are some technical details here and here, and comment here.

These issues last arose in 2003, when we fought back with the Trusted Computing FAQ and economic analysis. That initiative petered out after widespread opposition. This time round the effects could be even worse, as “unauthorised” operating systems like Linux and FreeBSD just won’t run at all. (On an old-fashioned Trusted Computing platform you could at least run Linux – it just couldn’t get at the keys for Windows Media Player.)

The extension of Microsoft’s OS monopoly to hardware would be a disaster, with increased lock-in, decreased consumer choice and lack of space to innovate. It is clearly unlawful and must not succeed.

Measuring Search-Redirection Attacks in the Illicit Online Prescription Drug Trade

Unauthorized online pharmacies that sell prescription drugs without requiring a prescription have been a fixture of the web for many years. Given the questionable legality of the shops’ business models, it is not surprising that most pharmacies resort to illegal methods for promoting their wares. Most prominently, email spam has relentlessly advertised illicit pharmacies. Researchers have measured the conversion rate of such spam, finding it to be surprisingly low. Upon reflection, this makes sense, given the spam’s unsolicited and untargeted nature. A more successful approach for the pharmacies would be to target users who have expressed an interest in purchasing drugs, such as those searching the web for online pharmacies. The trouble is that dodgy pharmacy websites don’t always garner the highest PageRanks on their own merits, and so some form of black-hat search-engine optimization may be required in order to appear near the top of web search results.

Indeed, by gathering daily the top search web results for 218 drug-related queries over nine months in 2010-2011, Nektarios Leontiadis, Nicolas Christin and I have found evidence of substantial manipulation of web search results to promote unauthorized pharmacies. In particular, we find that around one-third of the collected search results were one of 7,000 infected hosts triggered to redirect to a few hundred pharmacy websites. In the pervasive search-redirection attacks, miscreants compromise high-ranking websites and dynamically redirect traffic different pharmacies based on the particular search terms issued by the consumer. The full details of the study can be found in a paper appearing this week at the 20th USENIX Security Symposium in San Francisco.
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Phone hacking, technology and policy

Britain’s phone hacking scandal touches many issues of interest to security engineers. Murdoch’s gumshoes listened to celebs’ voicemail messages using default PINs. They used false-pretext phone calls – blagging – to get banking and medical records.

We’ve known for years that private eyes blag vast amounts of information (2001 book, from page 167; 2006 ICO Report). Centralisation and the ‘Cloud’ are making things worse. Twenty years ago, your bank records were available only in your branch; now any teller at any branch can look them up. The dozen people who work at your doctor’s surgery used to be able to keep a secret, but the 840,000 staff with a logon to our national health databases?

Attempts to fix the problem using the criminal justice system have failed. When blagging was made illegal in 1995, the street price of medical records actually fell from £200 to £150! Parliament increased the penalty from fines to jail in 2006 but media pressure scared ministers off implementing this law.

Our Database State report argued that the wholesale centralisation of medical and other records was unsafe and illegal; and the NHS Population Demographics Service database appears to be the main one used to find celebs’ ex-directory numbers. Celebs can opt out, but most of them are unaware of PDS abuse, so they don’t. Second, you can become a celeb instantly if you are a victim of crime, war or terror. Third, even if you do opt out, the gumshoes can just bribe policemen, who have access to just about everything.

In future, security engineers must pay much more attention to compartmentation (even the Pentagon is now starting to get it), and we must be much more wary about the risk that law-enforcement access to information will be abused.

The Sony hack: passwords vs. financial details

Sometime last week, Sony discovered that up to 77 M accounts on its PlayStation Network were compromised. Sony’s network was down for a week before they finally disclosed details yesterday. Unusually, there haven’t yet been any credible claims of responsibility for the hack, so we can only go on Sony’s official statements. The breach included names and addresses, passwords, and answers to personal knowledge questions, and possibly payment details. The risks of leaking payment card numbers are well-known, including fraudulent payment transactions and identity theft. Sony has responded by offering to provide free credit checks for affected customers and notifying major credit ratings bureaus with a list of affected customers. This hasn’t been enough for many critics, including a US Senator.

Still, this is far more than Sony has done regarding the leaked passwords. The risks here are very real—hackers can attempt to re-use the compromised passwords (possibly after inverting hashes using brute-force) at many other websites, including financial ones. There are no disclosure laws here though, and Sony has done nothing, not even disclosing the key technical details of how passwords were stored. The implications are very different if the passwords were stored in cleartext, hashed in a constant manner, or properly hashed and salted. Sony customers ought to know what really happened. Instead, towards the bottom of Sony’s FAQ they trail off mid sentence when discussing the leaked passwords:

Additionally, if you use the same user name or password for your PlayStation Network or Qriocity service account for other [no further text]

As we explored last summer, this is a serious market failure. Sony’s security breach has potentially compromised passwords at hundreds of other sites where its users re-use the same password and email address as credentials. This is a significant externality, but Sony bears no legal responsibility, and it shows. The options are never great once a breach has occurred, but Sony should at a minimum have promptly provided full details about their password storage, gave clear instructions to users to change their password at other sites, and notified at least the email providers of each account holder to instruct a forced password reset. The legal framework surrounding password breaches must catch up to that for financial breaches.

Resilience of the Internet Interconnection Ecosystem

The Internet is, by very definition, an interconnected network of networks. The resilience of the way in which the interconnection system works is fundamental to the resilience of the Internet. Thus far the Internet has coped well with disasters such as 9/11 and Hurricane Katrina – which have had very significant local impact, but the global Internet has scarcely been affected. Assorted technical problems in the interconnection system have caused a few hours of disruption but no long term effects.

But have we just been lucky ? A major new report, just published by ENISA (the European Network and Information Security Agency) tries to answer this question.

The report was written by Chris Hall, with the assistance of Ross Anderson and Richard Clayton at Cambridge and Panagiotis Trimintzios and Evangelos Ouzounis at ENISA. The full report runs to 238 pages, but for the time-challenged there’s a shorter 31 page executive summary and there will be a more ‘academic’ version of the latter at this year’s Workshop on the Economics of Information Security (WEIS 2011).
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Can we Fix Federated Authentication?

My paper Can We Fix the Security Economics of Federated Authentication? asks how we can deal with a world in which your mobile phone contains your credit cards, your driving license and even your car key. What happens when it gets stolen or infected?

Using one service to authenticate the users of another is an old dream but a terrible tar-pit. Recently it has become a game of pass-the-parcel: your newspaper authenticates you via your social networking site, which wants you to recover lost passwords by email, while your email provider wants to use your mobile phone and your phone company depends on your email account. The certification authorities on which online trust relies are open to coercion by governments – which would like us to use ID cards but are hopeless at making systems work. No-one even wants to answer the phone to help out a customer in distress. But as we move to a world of mobile wallets, in which your phone contains your credit cards and even your driving license, we’ll need a sound foundation that’s resilient to fraud and error, and usable by everyone. Where might this foundation be? I argue that there could be a quite surprising answer.

The paper describes some work I did on sabbatical at Google and will appear next week at the Security Protocols Workshop.

Why the Cabinet Office's £27bn cyber crime cost estimate is meaningless

Today the UK Cabinet Office released a report written by Detica. The report concluded that the annual cost of cyber crime in UK is £27bn. That’s less than $1 trillion, as AT&T’s Ed Amoroso testified before the US Congress in 2009. But it’s still a very large number, approximately 2% of UK GDP. If the total is accurate, then cyber crime is a very serious problem of utmost national importance.

Unfortunately, much of the total cost is based on questionable calculations that are impossible for outsiders to verify. 60% of the total cost is ascribed to intellectual property theft (i.e., business secrets not copied music and films) and espionage. The report does describe a methodology for how it arrived at the figures. However, several key details are lacking. To calculate the IP and espionage losses, the authors first calculated measures of each sector’s value to the economy. Then they qualitatively assessed how lucrative and feasible these attacks would be in each sector.

This is where trouble arises. Based on these assessments, the authors assigned a sector-specific probability of theft, one for the best-, worst- and average cases. Unfortunately, these probabilities are not specified in the report, and no detailed rationale is given for their assignment. Are the probabilities based on surveys of firms that have fallen victim to these particular types of crime? Or is it a number simply pulled from the air based on the hunch of the authors? It is impossible to determine from the report.
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Everyone’s spam is unique

How much spam you get depends on three main things, how many spammers know (or guess) your email address, how good your spam filtering is, and of course, how active the spammers are.

A couple of years back I investigated how spam volumes varied depending on the first letter of your email address (comparing aardvark@example.com with zebra@example.com), with the variations almost certainly coming down to “guessability” (an email address of john@ is easier to guess than yvette@).

As to the impact of filtering, I investigated spam levels in the aftermath of the disabling of McColo — asking whether it was the easy-to-block spam that disappeared? The impact of that closure will have been different for different people, depending on the type (and relative effectiveness) of their spam filtering solution.

Just at the moment, as reported upon in some detail by Brian Krebs, we’re seeing a major reduction in activity. In particular, the closure of an affiliate system for pharmacy spam in September reduced global spam levels considerably, and since Christmas a number of major systems have practically disappeared.

I’ve had a look at spam data going back to January 2010 from my own email server, which handles email for a handful of domains, and that shows a different story!

It shows that spam was up in October … so the reduction didn’t affect how many of the spam emails came to me, just how many “me’s” there were worldwide. Levels have been below the yearly average for much of December, but I am seeing most (but not all of) the dropoff since Christmas Day.

Click on the graph for an bigger version… and yes, the vertical axis is correct, I really do get up to 60,000 spam emails a day, and of course none at all on the days when the server breaks altogether.

Wikileaks, security research and policy

A number of media organisations have been asking us about Wikileaks. Fifteen years ago we kicked off the study of censorship resistant systems, which inspired the peer-to-peer movement; we help maintain Tor, which provides the anonymous communications infrastructure for Wikileaks; and we’ve a longstanding interest in information policy.

I have written before about governments’ love of building large databases of sensitive data to which hundreds of thousands of people need access to do their jobs – such as the NHS spine, which will give over 800,000 people access to our health records. The media are now making the link. Whether sensitive data are about health or about diplomacy, the only way forward is compartmentation. Medical records should be kept in the surgery or hospital where the care is given; and while an intelligence analyst dealing with Iraq might have access to cables on Iraq, Iran and Saudi Arabia, he should have no routine access to stuff on Korea or Brazil.

So much for the security engineering; now to policy. No-one questions the US government’s right to try one of its soldiers for leaking the cables, or the right of the press to publish them now that they’re leaked. But why is Wikileaks treated as the leaker, rather than as a publisher?

This leads me to two related questions. First, does a next-generation censorship-resistant system need a more resilient technical platform, or more respectable institutions? And second, if technological change causes respectable old-media organisations such as the Guardian and the New York Times to go bust and be replaced by blogs, what happens to freedom of the press, and indeed to freedom of speech?