The keynote talk was by Sunny Consolvo, who runs Google’s security and privacy UX team, and her topic was user-facing threats to privacy and security. Her first theme was browser warnings, which try to stop users doing what they want to; it’s an interruption, it’s technical and there’s no obvious way forward other than clicking through the warning. In 2013 their SSL warning had a clickthrough rate of 68% while their more explicit and graphic malware warning had only 23% clickthrough. Mozilla’s SSL warning had a much lower 33%, with an icon of a policeman and more explicit tests. After four years of experimenting with watching eyes, corporate styling / branding and extra steps – none of which worked very well – they tried a strategy of clear instruction, attractive preferred choice, and unattractive alternative. The text had less jargon, a low reading level, brevity, specifics, an illustration and colour. Her CHI15 paper shows that the new design did much better, from 69% CTR to 41%. It turns out that many factors are at play; a strong signal is site quality, but this leads many people to continue anyway to sites they have come to trust. The malware clickthrough rate is now down to 5%, and SSL to 21%. That cost five years of a huge team effort, with back-end stuff too as well as UX. It involved huge internal fights, such as with a product manager who wanted the warning to say “this site contains malware” rather than “the site you’re trying to get to contains malware” as it was shorter. Her recent papers are here, here, and here.
A second thread of work is a longitudonal survey of public opinion on privacy ranging from government surveillance to cyber-bullying. This has run since 2015 in sixteen countries. 84% of respondents thought limiting access to online but not public data is very or extremely important. 84% were concerned about hackers vs 55% worried about governments and 53% companies. 20% of Germans are very angry about government access to personal data versus 10% of Brits. Most people believe national security justifies data access (except in South Korea) while no country’s people believes the government should have access to police non-violent crime. Most people everywhere support targeted monitoring but nowhere is there majority support for bulk surveillance. In Germany 53% believed everyone should have the right to send anonymous encrypted email while in the UK it’s 39%. Germans were pessimistic about technology with only 4% believing it was possible to be completely anonymous online. Over 88% believe that freedom of expression is very or extremely important and less than 1% unimportant; but over 70% didn’t believe that cyberbullying should be allowed. Opinions are more varied on extremist religious content, with 10.9% agreeing it should be allowed and 21% saying “it depends”.
Her third thread was intimate partner abuse, which has been experienced by 27% of women and 11% of men. There are typically three phases: a physical control phase where the abuser has access to the survivor’s device and may install malware, or even destroy devices; an escape phase which is high-risk as they try to find a new home, a job and so on; and a life-apart phase when they might want to shield location, email address and phone numbers to escape harassment, and may have lifelong concerns. Risks are greater for poorer people who may not be able to just buy a new phone. Sunny gave some case stories of extreme mate guarding and survivors’ strategies such as using a neighbour’s phone or a computer in a library or at work. It takes seven escape attempts on average to get to life apart. After escape, a survivor may have to restrict childrens’ online activities and sever mutual relationships; letting your child post anything can leak the school location and lead to the abuser turning up. She may have to change career as it can be impossible to work as a self-employed professional if she can no longer advertise. The takeaway is that designers should focus on usability during times of high stress and high risk; they should allow users to have multiple accounts; they should design things so that someone reviewing your history should not be able to tell you deleted anything; they should push 2-factor authentication, unusual activity notifications, and incognito mode. They should also think about how a survivor can capture evidence for use in divorce and custody cases while minimising the trauma. Finally she suggests serious research on other abuse survivors of different age groups and in different countries. For more see her paper here.
I will try to liveblog the rest of the talks in followups to this post.
Mark Zuckerberg tried to blame Cambridge University in his recent testimony before the US Senate, saying “We do need to understand whether there was something bad going on in Cambridge University overall, that will require a stronger action from us.”
The New Scientist invited me to write a rebuttal piece, and here it is.
Dr Kogan tried to get approval to use the data his company had collected from Facebook users in academic research. The psychology ethics committee refused permission, and when he appealed to the University Ethics Committee (declaration: I’m a member) this refusal was upheld. Although he’d got consent from the people who ran his app, the same could not be said of their Facebook “friends” from whom most of the data were collected.
The deceptive behaviour here has been by Facebook, which creates the illusion of privacy in order to get its users to share more data. There has been a lot of work on the economics and psychology of privacy over the past decade and we now understand the dynamics of advertising markets better than we used to.
One big question is the “privacy paradox”. Why do people say they care about privacy, yet behave otherwise? Part of the answer is about context; and part of it is about learning. Over time, more and more people are starting to pay attention to online privacy settings, despite attempts by Facebook and other online advertising firms to keep changing privacy settings to confuse people.
With luck, the Facebook scandal will be a “flashbulb moment” that will drive lots more people to start caring about their privacy online. It will certainly provide interesting new data to privacy researchers.
What Goes Around Comes Around is a chapter I wrote for a book by EPIC. What are America’s long-term national policy interests (and ours for that matter) in surveillance and privacy? The election of a president with a very short-term view makes this ever more important.
While Britain was top dog in the 19th century, we gave the world both technology (steamships, railways, telegraphs) and values (the abolition of slavery and child labour, not to mention universal education). America has given us the motor car, the Internet, and a rules-based international trading system – and may have perhaps one generation left in which to make a difference.
Lessig taught us that code is law. Similarly, architecture is policy. The architecture of the Internet, and the moral norms embedded in it, will be a huge part of America’s legacy, and the network effects that dominate the information industries could give that architecture great longevity.
So if America re-engineers the Internet so that US firms can microtarget foreign customers cheaply, so that US telcos can extract rents from foreign firms via service quality, and so that the NSA can more easily spy on people in places like Pakistan and Yemen, then in 50 years’ time the Chinese will use it to manipulate, tax and snoop on Americans. In 100 years’ time it might be India in pole position, and in 200 years the United States of Africa.
My book chapter explores this topic. What do the architecture of the Internet, and the network effects of the information industries, mean for politics in the longer term, and for human rights? Although the chapter appeared in 2015, I forgot to put it online at the time. So here it is now.
The Economist features face recognition on its front page, reporting that deep neural networks can now tell whether you’re straight or gay better than humans can just by looking at your face. The research they cite is a preprint, available here.
Its authors Kosinski and Wang downloaded thousands of photos from a dating site, ran them through a standard feature-extraction program, then classified gay vs straight using a standard statistical classifier, which they found could tell the men seeking men from the men seeking women. My students pretty well instantly called this out as selection bias; if gay men consider boyish faces to be cuter, then they will upload their most boyish photo. The paper authors suggest their finding may support a theory that sexuality is influenced by fetal testosterone levels, but when you don’t control for such biases your results may say more about social norms than about phenotypes.
Quite apart from the scientific value of the research, which is perhaps best assessed by specialists, I’m concerned with the ethics and privacy aspects. I am surprised that the paper doesn’t report having been through ethical review; the authors consider that photos on a dating website are public information and appear to assume that privacy issues simply do not arise.
Yet UK courts decided, in Campbell v Mirror, that privacy could be violated even by photos taken on the public street, and European courts have come to similar conclusions in I v Finland and elsewhere. For example, a Catholic woman is entitled to object to the use of her medical record in research on abortifacients and contraceptives even if the proposed use is fully anonymised and presents no privacy risk whatsoever. The dating site users would be similarly entitled to object to their photos being used in research to which they might have an ethical objection, even if they could not be identified from their photos. There are surely going to be people who object to research in any nature vs nurture debate, especially on a charged topic such as sexuality. And the whole point of the Economist’s coverage is that face-recognition technology is now good enough to work at population scale.
Now that everyone’s distracted with the supreme court case on Brexit, you can expect the government to sneak out something it’s ashamed of. Health secretary Jeremy Hunt has decided to ignore the wishes of over a million people who opted out of having their hospital records given to third parties such as drug companies, and the ICO has decided to pretend that the anonymisation mechanisms he says he’ll use instead are sufficient. One gently smoking gun is the fifth bullet in a new webpage here, where the Department of Health claims that when it says the data are anonymous, your wishes will be ignored. The news has been broken in an article in the Health Services Journal (it’s behind a paywall, as a splendid example of transparency) with the Wellcome Trust praising the ICO’s decision not to take action against the Department. We are assured that “the data is seen as crucial for vital research projects”. The exchange of letters with privacy campaigners that led up to this decision can be found here, here, here, here, here, here, and here.
An early portent of this u-turn was reported here in 2014 when officials reckoned that the only way they could still do administrative tasks such as calculating doctors’ bonuses was to just pretend that the data are anonymous even though they know it isn’t really. Then, after the care.data scandal showed that a billion records had been sold to over a thousand purchasers, we reported here how HES data had also been sold and how the minister seemed to have misled parliament about this.
I will be talking about ethics of all this on Thursday. Even if ministers claim that stolen medical records are OK to use, researchers must not act as if this is true; if patients end up trusting doctors as little as we trust politicians, then medical research will be in serious trouble. There is a video of a previous version of this talk here.
Meanwhile, if you’re annoyed that Jeremy Hunt proposes to ignore not just your privacy rights but your express wishes, you can send him a notice under Section 10 of the Data Protection Act forbidding him from disclosing your data. The Department has complied with such notices in the past, albeit with bad grace as they have no automated way to do it. If thousands of people serve such notices, they may finally have to stand up to the drug company lobbyists and write the missing software. For more, see here.
At our security group meeting on the 19th August, Sergei Skorobogatov demonstrated a NAND backup attack on an iPhone 5c. I typed in six wrong PINs and it locked; he removed the flash chip (which he’d desoldered and led out to a socket); he erased and restored the changed pages; he put it back in the phone; and I was able to enter a further six wrong PINs.
I really like the simplicity of the original assumption. The starting point of the research was that different crypto/RSA libraries use slightly different elimination methods and “cut-off” thresholds to find suitable prime numbers. They thought these differences should be sufficient to detect a particular cryptographic implementation and all that was needed were public keys. Petr et al confirmed this assumption. The best paper award is a well-deserved recognition as I’ve worked with and followed Petr’s activities closely.
The authors created a method for efficient identification of the source (software library or hardware device) of RSA public keys. It resulted in a classification of keys into more than dozen categories. This classification can be used as a fingerprint that decreases the anonymity of users of Tor and other privacy enhancing mailers or operators.
All that is a result of an analysis of over 60 million freshly generated keys from 22 open- and closed-source libraries and from 16 different smart-cards. While the findings are fairly theoretical, they are demonstrated with a series of easy to understand graphs (see above).
I can’t see an easy way to exploit the results for immediate cyber attacks. However, we started looking into practical applications. There are interesting opportunities for enterprise compliance audits, as the classification only requires access to datasets of public keys – often created as a by-product of internal network vulnerability scanning.
We found that software on your smartphone can infer words you type in other apps by monitoring the aggregate number of context switches and the number of hardware interrupts. These are readable by permissionless apps within the virtual procfs filesystem (mounted under /proc). Three previousresearchgroups had found that other files under procfs support side channels. But the files they used contained information about individual apps– e.g. the file /proc/uid_stat/victimapp/tcp_snd contains the number of bytes sent by “victimapp”. These files are no longer readable in the latest Android version.
We found that the “global” files – those that contain aggregate information about the system – also leak. So a curious app can monitor these global files as a user types on the phone and try to work out the words. We looked at smartphone keyboards that support “gesture typing”: a novel input mechanism democratized by SwiftKey, whereby a user drags their finger from letter to letter to enter words.
This work shows once again how difficult it is to prevent side channels: they come up in all sorts of interesting and unexpected ways. Fortunately, we think there is an easy fix: Google should simply disable access to all procfs files, rather than just the files that leak information about individual apps. Meanwhile, if you’re developing apps for privacy or anonymity, you should be aware that these risks exist.