Category Archives: Security psychology

Hacktivism, in Ukraine and Gaza

People who write about cyber-conflict often talk of hacktivists and other civilian volunteers who contribute in various ways to a cause. Might the tools and techniques of cybercrime enable its practitioners to be effective auxiliaries in a real conflict? Might they fall foul of the laws of war, and become unlawful combatants?

We have now measured hacktivism in two wars – in Ukraine and Gaza – and found that its effects appear to be minor and transient in both cases.

In the case of Ukraine, hackers supporting Ukraine attacked Russian websites after the invasion, followed by Russian hackers returning the compliment. The tools they use, such as web defacement and DDoS, can be measured reasonably well using resources we have developed at the Cambridge Cybercrime Centre. The effects were largely trivial, expressing solidarity and sympathy rather than making any persistent contribution to the conflict. Their interest in the conflict dropped off rapidly.

In Gaza, we see the same pattern. After Hamas attacked Israel and Israel declared war, there was a surge of attacks that peaked after a few days, with most targets being strategically unimportant. In both cases, discussion on underground cybercrime forums tailed off after a week. The main difference is that the hacktivism against Israel is one-sided; supporters of Palestine have attacked Israeli websites, but the number of attacks on Palestinian websites has been trivial.

Interop: One Protocol to Rule Them All?

Everyone’s worried that the UK Online Safety Bill and the EU Child Sex Abuse Regulation will put an end to end-to-end encryption. But might a law already passed by the EU have the same effect?

The Digital Markets Act ruled that users on different platforms should be able to exchange messages with each other. This opens up a real Pandora’s box. How will the networks manage keys, authenticate users, and moderate content? How much metadata will have to be shared, and how?

In our latest paper, One Protocol to Rule Them All? On Securing Interoperable Messaging, we explore the security tensions, the conflicts of interest, the usability traps, and the likely consequences for individual and institutional behaviour.

Interoperability will vastly increase the attack surface at every level in the stack – from the cryptography up through usability to commercial incentives and the opportunities for government interference.

Twenty-five years ago, we warned that key escrow mechanisms would endanger cryptography by increasing complexity, even if the escrow keys themselves can be kept perfectly secure. Interoperability is complexity on steroids.

Bugs still considered harmful

A number of governments are trying to mandate surveillance software in devices that support end-to-end encrypted chat; the EU’s CSA Regulation and the UK’s Online Safety bill being two prominent current examples. Colleagues and I wrote Bugs in Our Pockets in 2021 to point out what was likely to go wrong; GCHQ responded with arguments about child protection, which I countered in my paper Chat Control or Child Protection.

As lawmakers continue to discuss the policy, the latest round in the technical argument comes from the Rephrain project, which was tasked with evaluating five prototypes built with money from GCHQ and the Home Office. Their report may be worth a read.

One contender looks for known-bad photos and videos with software on both client and server, and is the only team with access to CSAM for training or testing (it has the IWF as a partner). However it has inadequate controls both against scope creep, and against false positives and malicious accusations.

Another is an E2EE communications tool with added profanity filter and image scanning, linked to age verification, with no safeguards except human moderation at the reporting server.

The other three contenders are nudity detectors with various combinations of age verification or detection, and of reporting to parents or service providers.

None of these prototypes comes close to meeting reasonable requirements for efficacy and privacy. So the project can be seen as empirical support for the argument we made in “Bugs”, namely that doing surveillance while respecting privacy is really hard.

Security economics course

Back in 2015 I helped record a course in security economics in a project driven by colleagues from Delft. This was launched as an EDX MOOC as well as becoming part of the Delft syllabus, and it has been used in many other courses worldwide. In Brussels, in December, a Ukrainian officer told me they use it in their cyber defence boot camp.

There’s been a lot of progress in security economics over the past seven years; see for example the liveblogs of the workshop on the economics of information security here. So it’s time to update the course, and we’ll be working on that between now and May.

If there are any topics you think we should cover, or any bugs you’d like to report, please get in touch!

WEIS 2022 call for papers

The 2022 Workshop on the Economics of Information Security will be held at Tulsa, Oklahoma, on 21-22 June 2022. Paper submissions are due by 28 February 2022. After two virtual events we’re eager to get back to meeting in person if we possibly can.

The program chairs for 2022 are Sadia Afroz and Laura Brandimarte, and here is the call for papers.

We originally set this as 20-21, being unaware that June 20 is the Juneteenth holiday in the USA. Sorry about that.

Anyway, we hope to see lots of you in Tulsa!

Bugs in our pockets?

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.