Category Archives: Politics

Bugs in our pockets?

Academic papers, Internet censorship, Legal issues, News coverage, Operating systems, Politics, Privacy technology, Security economics, Security psychology

In August, Apple announced a system to check all our iPhones for illegal images, then delayed its launch after widespread pushback. Yet some governments continue to press for just such a surveillance system, and the EU is due to announce a new child protection law at the start of December.

Now, in Bugs in our Pockets: The Risks of Client-Side Scanning, colleagues and I take a long hard look at the options for mass surveillance via software embedded in people’s devices, as opposed to the current practice of monitoring our communications. Client-side scanning, as the agencies’ new wet dream is called, has a range of possible missions. While Apple and the FBI talked about finding still images of sex abuse, the EU was talking last year about videos and text too, and of targeting terrorism once the argument had been won on child protection. It can also use a number of possible technologies; in addition to the perceptual hash functions in the Apple proposal, there’s talk of machine-learning models. And, as a leaked EU internal report made clear, the preferred outcome for governments may be a mix of client-side and server-side scanning.

In our report, we provide a detailed analysis of scanning capabilities at both the client and the server, the trade-offs between false positives and false negatives, and the side effects – such as the ways in which adding scanning systems to citizens’ devices will open them up to new types of attack.

We did not set out to praise Apple’s proposal, but we ended up concluding that it was probably about the best that could be done. Even so, it did not come close to providing a system that a rational person might consider trustworthy.

Even if the engineering on the phone were perfect, a scanner brings within the user’s trust perimeter all those involved in targeting it – in deciding which photos go on the naughty list, or how to train any machine-learning models that riffle through your texts or watch your videos. Even if it starts out trained on images of child abuse that all agree are illegal, it’s easy for both insiders and outsiders to manipulate images to create both false negatives and false positives. The more we look at the detail, the less attractive such a system becomes. The measures required to limit the obvious abuses so constrain the design space that you end up with something that could not be very effective as a policing tool; and if the European institutions were to mandate its use – and there have already been some legislative skirmishes – they would open up their citizens to quite a range of avoidable harms. And that’s before you stop to remember that the European Court of Justice struck down the Data Retention Directive on the grounds that such bulk surveillance, without warrant or suspicion, was a grossly disproportionate infringement on privacy, even in the fight against terrorism. A client-side scanning mandate would invite the same fate.

But ‘if you build it, they will come’. If device vendors are compelled to install remote surveillance, the demands will start to roll in. Who could possibly be so cold-hearted as to argue against the system being extended to search for missing children? Then President Xi will want to know who has photos of the Dalai Lama, or of men standing in front of tanks; and copyright lawyers will get court orders blocking whatever they claim infringes their clients’ rights. Our phones, which have grown into extensions of our intimate private space, will be ours no more; they will be private no more; and we will all be less secure.

Robots, manners and stress

Academic papers, Legal issues, Politics, Security engineering

Humans and other animals have evolved to be aware of whether we’re under threat. When we’re on safe territory with family and friends we relax, but when we sense that a rival or a predator might be nearby, our fight-or-flight response kicks in. Situational awareness is vital, as it’s just too stressful to be alert all the time.

We’ve started to realise that this is likely to be just as important in many machine-learning applications. Take as an example machine vision in an automatic driver assistance system, whose goal is automatic lane keeping and automatic emergency braking. Such systems use deep neural networks, as they perform way better than the alternatives; but they can be easily fooled by adversarial examples. Should we worry? Sure, a bad person might cause a car crash by projecting a misleading image on a motorway bridge – but they could as easily steal some traffic cones from the road works. Nobody sits up at night worrying about that. But the car industry does actually detune vision systems from fear of deceptive attacks!

We therefore started a thread of research aimed at helping machine-learning systems detect whether they’re under attack. Our first idea was the Taboo Trap. You raise your kids to observe social taboos – to behave well and speak properly – and yet once you send them to school they suddenly know words that would make your granny blush. The taboo violation shows they’ve been exposed to ‘adversarial inputs’, as an ML engineer would call them. So we worked out how to train a neural network to avoid certain taboo values, both of outputs (forbidden utterances) and intermediate activations (forbidden thoughts). The taboos can be changed every time you retrain the network, giving the equivalent of a cryptographic key. Thus even though adversarial samples will always exist, you can make them harder to find; an attacker can’t just find one that works against one model of car and use it against every other model. You can take a view, based on risk, of how many different keys you need.

We then showed how you can also attack the availability of neural networks using sponge examples – inputs designed to soak up as much energy, and waste as much time, as possible. An alarm can be simpler to build in this case: just monitor how long your classifier takes to run.

Are there broader lessons? We suspect so. As robots develop situational awareness, like humans, and react to real or potential attacks by falling back to a more cautious mode of operation, a hostile environment will cause the equivalent of stress. Sometimes this will be deliberate; one can imagine constant low-level engagement between drones at tense national borders, just as countries currently probe each others’ air defences. But much of the time it may well be a by-product of poor automation design coupled with companies hustling aggressively for consumers’ attention.

This suggests a missing factor in machine-learning research: manners. We’ve evolved manners to signal to others that our intent is not hostile, and to negotiate the many little transactions that in a hostile environment might lead to a tussle for dominance. Yet these are hard for robots. Food-delivery robots can become unpopular for obstructing and harassing other pavement users; and one of the show-stoppers for automated driving is the difficulty that self-driving cars have in crossing traffic, or otherwise negotiating precedence with other road users. And even in the military, manners have a role – from the chivalry codes of medieval knights to the more modern protocols whereby warships and warplanes warn other craft before opening fire. If we let loose swarms of killer drones with no manners, conflict will be more likely.

Our paper Situational Awareness and Machine Learning – Robots, Manners and Stress was invited as a keynote for two co-located events: IEEE CogSIMA and the NATO STO SCI-341 Research Symposium on Situation awareness of Swarms and Autonomous systems. We got so many conflicting demands from the IEEE that we gave up on making a video of the talk for them, and our paper was pulled from their proceedings. However we decided to put the paper online for the benefit of the NATO folks, who were blameless in this matter.

Infrastructure – the Good, the Bad and the Ugly

Cybercrime, Internet censorship, Legal issues, News coverage, Politics, Security economics, Social networks

Infrastructure used to be regulated and boring; the phones just worked and water just came out of the tap. Software has changed all that, and the systems our society relies on are ever more complex and contested. We have seen Twitter silencing the US president, Amazon switching off Parler and the police closing down mobile phone networks used by crooks. The EU wants to force chat apps to include porn filters, India wants them to tell the government who messaged whom and when, and the US Department of Justice has launched antitrust cases against Google and Facebook.

Infrastructure – the Good, the Bad and the Ugly analyses the security economics of platforms and services. The existence of platforms such as the Internet and cloud services enabled startups like YouTube and Instagram soar to huge valuations almost overnight, with only a handful of staff. But criminals also build infrastructure, from botnets through malware-as-a-service. There’s also dual-use infrastructure, from Tor to bitcoins, with entangled legitimate and criminal applications. So crime can scale too. And even “respectable” infrastructure has disruptive uses. Social media enabled both Barack Obama and Donald Trump to outflank the political establishment and win power; they have also been used to foment communal violence in Asia. How are we to make sense of all this?

I argue that this is not simply a matter for antitrust lawyers, but that computer scientists also have some insights to offer, and the interaction between technical and social factors is critical. I suggest a number of principles to guide analysis. First, what actors or technical systems have the power to exclude? Such control points tend to be at least partially social, as social structures like networks of friends and followers have more inertia. Even where control points exist, enforcement often fails because defenders are organised in the wrong institutions, or otherwise fail to have the right incentives; many defenders, from payment systems to abuse teams, focus on process rather than outcomes.

There are implications for policy. The agencies often ask for back doors into systems, but these help intelligence more than interdiction. To really push back on crime and abuse, we will need institutional reform of regulators and other defenders. We may also want to complement our current law-enforcement strategy of decapitation – taking down key pieces of criminal infrastructure such as botnets and underground markets – with pressure on maintainability. It may make a real difference if we can push up offenders’ transaction costs, as online criminal enterprises rely more on agility than on on long-lived, critical, redundant platforms.

This was a Dertouzos Distinguished Lecture at MIT in March 2021.

Friendly neighbourhood cybercrime: online harm in the pandemic and the futures of cybercrime policing

Academic papers, Cybercrime, Politics

As cybercrime researchers we’re often focused on the globalised aspects of online harms – how the Internet connects people and services around the world, opening up opportunities for crime, risk, and harm on a global scale. However, as we argue in open access research published this week in the Journal of Criminal Psychology in collaboration between the Cambridge Cybercrime Centre (CCC), Edinburgh Napier University, the University of Edinburgh, and Abertay University, as we have seen an enormous rise in reported cybercrime in the pandemic, we have paradoxically seen this dominated by issues with a much more local character. Our paper sketches a past: of cybercrime in a turbulent 2020, and a future: of the roles which state law enforcement might play in tackling online harm a post-pandemic world.

Continue reading Friendly neighbourhood cybercrime: online harm in the pandemic and the futures of cybercrime policing →

WEIS 2020 – Liveblog

Authentication, Cybercrime, Legal issues, Politics, Security economics, Security psychology

I’ll be trying to liveblog the seventeenth Workshop on the Economics of Information Security (WEIS), which is being held online today and tomorrow (December 14/15) and streamed live on the CEPS channel on YouTube. The event was introduced by the general chair, Lorenzo Pupillo of CEPS, and the program chair Nicolas Christin of CMU. My summaries of the sessions will appear as followups to this post, and videos will be linked here in a few days.

SHB Seminar

Academic papers, Politics, Privacy technology, Security economics, Security psychology, Seminars

The SHB seminar on November 5th was kicked off by Tom Holt, who’s discovered a robust underground market in identity documents that are counterfeit or fraudulently obtained. He’s been scraping both websites and darkweb sites for data and analysing how people go about finding, procuring and using such credentials. Most vendors were single-person operators although many operate within affiliate programs; many transactions involved cryptocurrency; many involve generating pdfs that people can print at home and that are good enough for young people to drink alcohol. Curiously, open web products seem to cost twice as much as dark web products.

Next was Jack Hughes, who has been studying the contract system introduced by hackforums in 2018 and made mandatory the following year. This enabled him to analyse crime forum behaviour before and during the covid-19 era. How do new users become active, and build up trust? How does it evolve? He collected 200,000 transactions and analysed them. The contract mandate stifled growth quickly, leading to a first peak; covid caused a second. The market was already centralised, and became more so with the pandemic. However contracts are getting done faster, and the main activity is currency exchange: it seems to be working as a cash-out market.

Anita Lavorgna has been studying the discourse of groups who oppose public mask mandates. Like the antivaxx movement, this can draw in fringe groups and become a public-health issue. She collected 23654 tweets from February to June 2020. There’s a diverse range of voices from different places on the political spectrum but with a transversal theme of freedom from government interference. Groups seek strength in numbers and seek to ally into movements, leading to the mask becoming a symbol of political identity construction. Anita found very little interaction between the different groups: only 144 messages in total.

Simon Parkin has been working on how we can push back on bad behaviours online while they are linked with good behaviours that we wish to promote. Precision is hard as many of the desirable behaviours are not explicitly recognised as such, and as many behaviours arise as a combination of personal incentives and context. The best way forward is around usability engineering – making the desired behaviours easier.

Bruce Schneier was the final initial speaker, and his topic was covid apps. The initial rush of apps that arrived in March through June have known issues around false positives and false negatives. We’ve also used all sorts of other tools, such as analysis of Google maps to measure lockdown compliance. The third thing is the idea of an immunity passport, saying you’ve had the disease, or a vaccine. That will have the same issues as the fake IDs that Tom talked about. Finally, there’s compliance tracking, where your phone monitors you. The usual countermeasures apply: consent, minimisation, infosec, etc., though the trade-offs might be different for a while. A further bunch of issues concern home working and the larger attack surface that many firms have as a result of unfamiliar tools, less resistance to being tols to do things etc.

The discussion started on fake ID; Tom hasn’t yet done test purchases, and might look at fraudulently obtained documents in the future, as opposed to completely counterfeit ones. Is hackforums helping drug gangs turn paper into coin? This is not clear; more is around cashing out cybercrime rather than street crime. There followed discussion by Anita of how to analyse corpora of tweets, and the implications for policy in real life. Things are made more difficult by the fact that discussions drift off into other platforms we don’t monitor. Another topic was the interaction of fashion: where some people wear masks or not as a political statement, many more buy masks that get across a more targeted statement. Fashion is really powerful, and tends to be overlooked by people in our field. Usability research perhaps focuses too much on the utilitarian economics, and is a bit of a blunt instrument. Another example related to covid is the growing push for monitoring software on employees’ home computers. Unfortunately Uber and Lyft bought a referendum result that enables them to not treat their staff in California as employees, so the regulation of working hours at home will probably fall to the EU. Can we perhaps make some input into what that should look like? Another issue with the pandemic is the effect on information security markets: why should people buy corporate firewalls when their staff are all over the place? And to what extent will some of these changes be permanent, if people work from home more? Another thread of discussion was how the privacy properties of covid apps make it hard for people to make risk-management decisions. The apps appear ineffective because they were designed to do privacy rather than to do public health, in various subtle ways; giving people low-grade warnings which do not require any action appear to be an attempt to raise public awareness, like mask mandates, rather than an effective attempt to get exposed individuals to isolate. Apps that check people into venues have their own issues and appear to be largely security theatre. Security theatre comes into its own where the perceived risk is much greater than the actual risk; covid is the opposite. What can be done in this case? Targeted warnings? Humour? What might happen when fatigue sets in? People will compromise compliance to make their lives bearable. That can be managed to some extent in institutions like universities, but in society it will be harder. We ended up with the suggestion that the next SHB seminar should be in February, which should be the low point; after that we can look forward to things getting better, and hopefully to a meeting in person in Cambridge on June 3-4 2021.

Our new “Freedom of Speech” policy

Electronic voting, Legal issues, News coverage, Politics

Our beloved Vice-Chancellor proposes a “free speech” policy under which all academics must treat other academics with “respect”. This is no doubt meant well, but the drafting is surprisingly vague and authoritarian for a university where the VC, the senior pro-VC, the HR pro-VC and the Registrary are all lawyers. The bottom line is that in future we might face disciplinary charges and even dismissal for mockery of ideas and individuals with which we disagree.

The policy was slipped out in March, when nobody was paying attention. There was a Discussion in June, at which my colleague Arif Ahmad spelled out the problems.

Vigorous debate is intrinsic to academia and it should be civil, but it is unreasonable to expect people to treat all opposing views with respect. Oxford’s policy spells this out. At the Discussion, Arif pointed out that “respect” must be changed to “tolerance” if we are to uphold the liberal culture that we have not just embraced but developed over several centuries.

At its first meeting this term, the University Council considered these arguments but decided to press ahead anyway. We are therefore calling a ballot on three amendments to the policy. If you’re a senior member of the University we invite you to sign up your support for them on the flysheets. The first amendment changes “respect” to “tolerance”; the second makes it harder to force university societies to disinvite speakers whose remarks may be controversial, and the third restricts the circumstances in which the university itself can ban speakers.

Liberalism is coming under attack from authoritarians of both left and right, yet it is the foundation on which modern academic life is built and our own university has contributed more than any other to its development over the past 811 years. If academics can face discipline for using tactics such as scorn, ridicule and irony to criticise folly, how does that sit with having such alumni as John Maynard Keynes and Charles Darwin, not to mention Bertrand Rusell, Douglas Adams and Salman Rushdie?

Of testing centres, snipe, and wild geese: COVID briefing paper #8

Legal issues, Politics 
Does the road wind up-hill all the way?
   Yes, to the very end.
Will the day's journey take the whole long day?
   From morn to night, my friend.

Christina Rossetti, 1861: Up-Hill.

This week’s COVID briefing paper takes a personal perspective as I recount my many adventures in complying with a call for testing from my local council.

So as to immerse the reader in the experience, this post is long. If you don’t have time for that, you can go directly to the briefing.

The council calls for everyone in my street to be tested

On Thursday 13 August my household received a hand-delivered letter from the chief executive of my local council. There had been an increase in cases in my area, and as a result, they were asking everyone on my street to get tested.

Dramatis personae:

  • ME, a knowledge worker who has structured her life so as to minimize interaction with the outside world until the number of daily cases drops a lot lower than it is now;
  • OTHER HOUSEHOLD MEMBERS, including people with health conditions, who would be shielding if shielding hadn’t ended on August 1.

Fortunately, everyone else in my household is also in a position to enjoy the mixed blessing of a lifestyle without social interaction. So, none of us reacted to the news of an outbreak amongst our neighbours with fear for our own health, considering our habits over the last six months. Rather, we were, and are, reassured that the local government was taking a lead.

My neighbour, however, was having a different experience. Like most people on our street, he does not have the same privileges I do: he works in a supermarket, he does not have a car, and his only Internet access is through his dumbphone. Days before, he had texted me at the end of his tether, because customers were not wearing masks or observing social distancing. He felt (because he is) unprotected, and said it was only a matter of time before he becomes infected. Receiving the council’s letter only reinforced his alarm.

Booking the tests

Continue reading Of testing centres, snipe, and wild geese: COVID briefing paper #8 →

Security and Human Behaviour 2020

Academic papers, Cybercrime, Politics, Privacy technology, Security economics, Security psychology, Usability

I’ll be liveblogging the workshop on security and human behaviour, which is online this year. My liveblogs will appear as followups to this post. This year my program co-chair is Alice Hutchings and we have invited a number of eminent criminologists to join us. Edited to add: here are the videos of the sessions.