Monthly Archives: January 2014

Why bouncing droplets are a pretty good model of quantum mechanics

Academic papers, Cryptology

Today Robert Brady and I publish a paper that solves an outstanding problem in physics. We explain the beautiful bouncing droplet experiments of Yves Couder, Emmanuel Fort and their colleagues.

For years now, people interested in the foundations of physics have been intrigued by the fact that droplets bouncing on a vibrating tray of fluid can behave in many ways like quantum mechanical particles, with single-slit and double-slit diffraction, tunneling, Anderson localisation and quantised orbits.

In our new paper, Robert Brady and I explain why. The wave field surrounding the droplet is, to a good approximation, Lorentz covariant with the constant c being the speed of surface waves. This plus the inverse square force between bouncing droplets (which acts like the Coulomb force) gives rise to an analogue of the magnetic force, which can be observed clearly in the droplet data. There is also an analogue of the Schrödinger equation, and even of the Pauli exclusion principle.

These results not only solve a fascinating puzzle, but might perhaps nudge more people to think about novel models of quantum foundations, about which we’ve written three previous papers.

Call for Papers: 14th Privacy Enhancing Technologies Symposium (PETS 2014)

Call for papers, Privacy technology

The Privacy Enhancing Technologies Symposium (PETS) aims to advance the state of the art and foster a world-wide community of researchers and practitioners to discuss innovation and new perspectives.

PETS seeks paper submissions for its 14th event to be held in Amsterdam, Netherlands, July 16–18, 2014 (of which I am program chair). Papers should present novel practical and/or theoretical research into the design, analysis, experimentation, or fielding of privacy-enhancing technologies. While PETS has traditionally been home to research on anonymity systems and privacy-oriented cryptography, we strongly encourage submissions in a number of both well-established and some emerging privacy-related topics.

Abstracts should be submitted by 10 February 2014, with full papers submitted by 13 February 2014. For further details, see the call for papers.

Opting out of the latest NHS data grab

Legal issues, News coverage, Politics, Security economics, Security psychology

The next three weeks will see a leaflet drop on over 20 million households. NHS England plans to start uploading your GP records in March or April to a central system, from which they will be sold to a wide range of medical and other research organisations. European data-protection and human-rights laws demand that we be able to opt out of such things, so the Information Commissioner has told the NHS to inform you of your right to opt out.

Needless to say, their official leaflet is designed to cause as few people to opt out as possible. It should really have been drafted like this. (There’s a copy of the official leaflet at the MedConfidential.org website.) But even if it had been, the process still won’t meet the consent requirements of human-rights law as it won’t be sent to every patient. One of your housemates could throw it away as junk before you see it, and if you’ve opted out of junk mail you won’t get a leaflet at all.

Yet if you don’t opt out in the next few weeks your data will be uploaded to central systems and you will not be able to get it deleted, ever. If you don’t opt out your kids in the next few weeks the same will happen to their data, and they will not be able to get their data deleted even if they decide they prefer privacy once they come of age. If you opted out of the Summary Care Record in 2009, that doesn’t count; despite a ministerial assurance to the contrary, you now need to opt out all over again. For further information see the website of GP Neil Bhatia (who drafted our more truthful leaflet) and previous LBT posts on medical privacy.

"Perfectly" Encrypt 50 Letters By Hand

Protocols, Usability, Useful software,

When I read about cryptography before computers, I sometimes wonder why people did this and that instead of something a bit more secure. We may ridicule portable encryption systems based on monoalphabetic or even simple polyalphabetic ciphers but we may also change our opinion after actually trying it for real.
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Reading this may harm your computer

Academic papers, Legal issues, Security economics, Security psychology

David Modic and I have just published a paper on The psychology of malware warnings. We’re constantly bombarded with warnings designed to cover someone else’s back, but what sort of text should we put in a warning if we actually want the user to pay attention to it?

To our surprise, social cues didn’t seem to work. What works best is to make the warning concrete; people ignore general warnings such as that a web page “might harm your computer” but do pay attention to a specific one such as that the page would “try to infect your computer with malware designed to steal your bank account and credit card details in order to defraud you”. There is also some effect from appeals to authority: people who trust their browser vendor will avoid a page “reported and confirmed by our security team to contain malware”.

We also analysed who turned off browser warnings, or would have if they’d known how: they were people who ignored warnings anyway, typically men who distrusted authority and either couldn’t understand the warnings or were IT experts.

Anatomy of Passwords

Authentication, Protocols, Usability, Web security, , ,

Passwords have not really changed since they were first used. Let’s go down the memory lane a bit and then analyse how password systems work and how they could be improved. You may say – forget passwords, OTP is the way forward. My next question would then be: So why do we use OTP in combination with passwords when they are so good?
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