Category Archives: Seminars

Cambridge2Cambridge 2017

Following on from various other similar events we organised over the past few years, last week we hosted our largest ethical hacking competition yet, Cambridge2Cambridge 2017, with over 100 students from some of the best universities in the US and UK working together over three days. Cambridge2Cambridge was founded jointly by MIT CSAIL (in Cambridge Massachusetts) and the University of Cambridge Computer Laboratory (in the original Cambridge) and was first run at MIT in 2016 as a competition involving only students from these two universities. This year it was hosted in Cambridge UK and we broadened the participation to many more universities in the two countries. We hope in the future to broaden participation to more countries as well.

Cambridge 2 Cambridge 2017 from Frank Stajano Explains on Vimeo.

We assigned the competitors to teams that were mixed in terms of both provenance and experience. Each team had competitors from US and UK, and no two people from the same university; and each team also mixed experienced and less experienced players, based on the qualifier scores. We did so to ensure that even those who only started learning about ethical hacking when they heard about this competition would have an equal chance of being in the team that wins the gold. We then also mixed provenance to ensure that, during these three days, students collaborated with people they didn’t already know.

Despite their different backgrounds, what the attendees had in common was that they were all pretty smart and had an interest in cyber security. It’s a safe bet that, ten or twenty years from now, a number of them will probably be Security Specialists, Licensed Ethical Hackers, Chief Security Officers, National Security Advisors or other high calibre security professionals. When their institution or country is under attack, they will be able to get in touch with the other smart people they met here in Cambridge in 2017, and they’ll be in a position to help each other. That’s why the defining feature of the event was collaboration, making new friends and having fun together. Unlike your standard one-day hacking contest, the ambitious three-day programme of C2C 2017 allowed for social activities including punting on the river Cam, pub crawling and a Harry Potter style gala dinner in Trinity College.

In between competition sessions we had a lively and inspirational “women in cyber” panel, another panel on “securing the future digital society”, one on “real world pentesting” and a careers advice session. On the second day we hosted several groups of bright teenagers who had been finalists in the national CyberFirst Girls Competition. We hope to inspire many more women to take up a career path that has so far been very male-dominated. More broadly, we wish to inspire many young kids, girls or boys, to engage in the thrilling challenge of unravelling how computers work (and how they fail to work) in a high-stakes mental chess game of adversarial attack and defense.

Our platinum sponsors Leidos and NCC Group endowed the competition with over £20,000 of cash prizes, awarded to the best 3 teams and the best 3 individuals. Besides the main attack-defense CTF, fought on the Leidos CyberNEXS cyber range, our other sponsors offered additional competitions, the results of which were combined to generate the overall teams and individual scores. Here is the leaderboard, showing how our contestants performed. Special congratulations to Bo Robert Xiao of Carnegie Mellon University who, besides winning first place in both team and individuals, also went on to win at DEF CON in team PPP a couple of days later.

We are grateful to our supporters, our sponsors, our panelists, our guests, our staff and, above all, our 110 competitors for making this event a success. It was particularly pleasing to see several students who had already taken part in some of our previous competitions (special mention for Luke Granger-Brown from Imperial who earned medals at every visit). Chase Lucas from Dakota State University, having passed the qualifier but not having picked in the initial random selection, was on the reserve list in case we got funding to fly additional students; he then promptly offered to pay for his own airfare in order to be able to attend! Inter-ACE 2017 winner Io Swift Wolf from Southampton deserted her own graduation ceremony in order to participate in C2C (!), and then donated precious time during the competition to the CyberFirst girls who listened to her rapturously. Accumulating all that good karma could not go unrewarded, and indeed you can once again find her name in the leaderboard above. And I’ve only singled out a few, out of many amazing, dynamic and enthusiastic young people. Watch out for them: they are the ones who will defend the future digital society, including you and your family, from the cyber attacks we keep reading about in the media. We need many more like them, and we need to put them in touch with each other. The bad guys are organised, so we have to be organised too.

The event was covered by Sky News, ITV, BBC World Service and a variety of other media, which the official website and twitter page will undoubtedly collect in due course.

Emerging, fascinating, and disruptive views of quantum mechanics

I have just spent a long weekend at Emergent Quantum Mechanics (EmQM15). This workshop is organised every couple of years by Gerhard Groessing and is the go-to place if you’re interested in whether quantum mechanics dooms us to a universe (or multiverse) that can be causal or local but not both, or whether we might just make sense of it after all. It’s held in Austria – the home not just of the main experimentalists working to close loopholes in the Bell tests, such as Anton Zeilinger, but of many of the physicists still looking for an underlying classical model from which quantum phenomena might emerge. The relevance to the LBT audience is that the security proofs of quantum cryptography, and the prospects for quantum computing, turn on this obscure area of science.

The two themes emergent from this year’s workshop are both relevant to these questions; they are weak measurement and emergent global correlation.

Weak measurement goes back to the 1980s and the thesis of Lev Vaidman. The idea is that you can probe the trajectory of a quantum mechanical particle by making many measurements of a weakly coupled observable between preselection and postselection operations. This has profound theoretical implications, as it means that the Heisenberg uncertainty limit can be stretched in carefully chosen circumstances; Masanao Ozawa has come up with a more rigorous version of the Heisenberg bound, and in fact gave one of the keynote talks two years ago. Now all of a sudden there are dozens of papers on weak measurement, exploring all sorts of scientific puzzles. This leads naturally to the question of whether weak measurement is any good for breaking quantum cryptosystems. After some discussion with Lev I’m convinced the answer is almost certainly no; getting information about quantum states takes exponentially much work and lots of averaging, and works only in specific circumstances, so it’s easy for the designer to forestall. There is however a question around interdisciplinary proofs. Physicists have known about weak measurement since 1988 (even if few paid attention till a few years ago), yet no-one has rushed to tell the crypto community “Sorry, guys, when we said that nothing can break the Heisenberg bound, we kinda overlooked something.”

The second theme, emergent global correlation, may be of much more profound interest, to cryptographers and physicists alike.

Continue reading Emerging, fascinating, and disruptive views of quantum mechanics

Medical privacy seminar on May 4th

On Monday May 4th, the Dutch medical privacy campaigner Guido van’t Noordende will visit us in Cambridge. OK, it’s a bank holiday, but that’s the only day he’ll be in town. His talk will be on The Dutch electronic patient record system and beyond – towards physician-controlled decentralized medical record exchange.

Four years ago, Guido blocked an attempt to legislate for a central hub for medical records that would have enabled doctor A to see the records of doctor B on a simple pull model; there would have been a hub at the ministry with read access to everything. Other countries have wrestled with this problem, with greater and lesser degrees of success; for example, Norway just passed a medical data-sharing law and are starting to figure out what to build. In Britain of course we had the care.data fiasco. And in the Netherlands, they’re revisiting the issue once more. This will become a live issue in one country after another.

The announcement for Guido’s talk is here.

Talk in Oxford at 5pm today on the ethics and economics of privacy in a world of Big Data

Today at 5pm I’ll be giving the Bellwether Lecture at the Oxford Internet Institute. My topic is Big Conflicts: the ethics and economics of privacy in a world of Big Data.

I’ll be discussing a recent Nuffield Bioethics Council report of which I was one of the authors. In it, we asked what medical ethics should look like in a world of ‘Big Data’ and pervasive genomics. It will take the law some time to catch up with what’s going on, so how should researchers behave meanwhile so that the people whose data we use don’t get annoyed or surprised, and so that we can defend our actions if challenged? We came up with four principles, which I’ll discuss. I’ll also talk about how they might apply more generally, for example to my own field of security research.

There exists a classical model of the photon after all

Many people assume that quantum mechanics cannot emerge from classical phenomena, because no-one has so far been able to think of a classical model of light that is consistent with Maxwell’s equations and reproduces the Bell test results quantitatively.

Today Robert Brady and I unveil just such a model. It turns out that the solution was almost in plain sight, in James Clerk Maxwell’s 1861 paper On Phyiscal Lines of Force in which he derived Maxwell’s equations, on the assumption that magnetic lines of force were vortices in a fluid. Updating this with modern knowledge of quantised magnetic flux, we show that if you model a flux tube as a phase vortex in an inviscid compressible fluid, then wavepackets sent down this vortex obey Maxwell’s equations to first order; that they can have linear or circular polarisation; and that the correlation measured between the polarisation of two cogenerated wavepackets is exactly the same as is predicted by quantum mechanics and measured in the Bell tests.

This follows work last year in which we explained Yves Couder’s beautiful bouncing-droplet experiments. There, a completely classical system is able to exhibit quantum-mechanical behaviour as the wavefunction ψ appears as a modulation on the driving oscillation, which provides coherence across the system. Similarly, in the phase vortex model, the magnetic field provides the long-range order and the photon is a modulation of it.

We presented this work yesterday at the 2015 Symposium of the Trinity Mathematical Society. Our talk slides are here and there is an audio recording here.

If our sums add up, the consequences could be profound. First, it will explain why quantum computers don’t work, and blow away the security ‘proofs’ for entanglement-based quantum cryptosystems (we already wrote about that here and here). Second, if the fundamental particles are just quasiparticles in a superfluid quantum vacuum, there is real hope that we can eventually work out where all the mysterious constants in the Standard Model come from. And third, there is no longer any reason to believe in multiple universes, or effects that propagate faster than light or backward in time – indeed the whole ‘spooky action at a distance’ to which Einstein took such exception. He believed that action in physics was local and causal, as most people do; our paper shows that the main empirical argument against classical models of reality is unsound.

Why bouncing droplets are a pretty good model of quantum mechanics – seminar

Today Robert Brady and I will be giving a seminar in Cambridge where we will explain Yves Couder’s beautiful bouncing droplet experiments. Droplets bouncing on a vibrating fluid bath show many of the weird phenomena of quantum mechanics including tunneling, diffraction and quantized orbits.

We published a paper on this in January and blogged it at the time, but now we have more complete results. The two-dimensional model of electromagnetism that we see in bouncing droplets goes over to three dimensions too, giving us a better model of transverse sound in superfluids and a better explanation of the Bell test results. Here are the slides.

The talk will be at 4pm in the Centre for Mathematical Sciences.