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 →
We are presenting a paper at SPSM next week that shows that, on average over the last four years, 87% of Android devices are vulnerable to attack by malicious apps. This is because manufacturers have not provided regular security updates. Some manufacturers are much better than others however, and our study shows that devices built by LG and Motorola, as well as those devices shipped under the Google Nexus brand are much better than most. Users, corporate buyers and regulators can find further details on manufacturer performance at AndroidVulnerabilities.org
We used data collected by our Device Analyzer app, which is available from the Google Play Store. The app collects data from volunteers around the globe and we have used data from over 20,000 devices in our study. As always, we are keen to recruit more contributors! We combined Device Analyzer data with information we collected on critical vulnerabilities affecting Android. We used this to develop the FUM score which can be used to compare the security provided by different manufacturers. Each manufacturer is given a score out of 10 based on: f, the proportion of devices free from known critical vulnerabilities; u, the proportion of devices updated to the most recent version; and m, the mean number of vulnerabilities the manufacturer has not fixed on any device.
The problem with the lack of updates to Android devices is well known and recently Google and Samsung have committed to shipping security updates every month. Our hope is that by quantifying the problem we can help people when choosing a device and that this in turn will provide an incentive for other manufacturers and operators to deliver updates.
Google has done a good job at mitigating many of the risks, and we recommend users only install apps from Google’s Play Store since it performs additional safety checks on apps. Unfortunately Google can only do so much, and recent Android security problems have shown that this is not enough to protect users. Devices require updates from manufacturers, and the majority of devices aren’t getting them.
For further information, contact Daniel Thomas and Alastair Beresford via firstname.lastname@example.org
The Cambridge Cloud Cybercrime Centre formally started work this week … but rather than writing about that I thought I’d document some publicly visible artefacts of improper behaviour (much of which, my experience tells me, is very likely to do with the sending of email spam).
RIPE is one of the five Regional Internet Registries (RIRs) and they have the responsibility of making allocations of IP address space to entities in Europe and the Middle East (ARIN deals with North America, APNIC with Asia and Australasia, LACNIC with Latin America and the Caribbean and AfriNIC with Africa).
Their public “WHOIS” databases documents these allocations and there are web interfaces to access them (for RIPE use https://apps.db.ripe.net/search/query.html).
The RIPE Database also holds a number of other sets of data including a set of “routes”. Unfortunately some of those routes are prima facie evidence of people behaving badly.
Continue reading Badness in the RIPE Database →