Category Archives: Internet censorship

Security Engineering: Third Edition

I’m writing a third edition of my best-selling book Security Engineering. The chapters will be available online for review and feedback as I write them.

Today I put online a chapter on Who is the Opponent, which draws together what we learned from Snowden and others about the capabilities of state actors, together with what we’ve learned about cybercrime actors as a result of running the Cambridge Cybercrime Centre. Isn’t it odd that almost six years after Snowden, nobody’s tried to pull together what we learned into a coherent summary?

There’s also a chapter on Surveillance or Privacy which looks at policy. What’s the privacy landscape now, and what might we expect from the tussles over data retention, government backdoors and censorship more generally?

There’s also a preface to the third edition.

As the chapters come out for review, they will appear on my book page, so you can give me comment and feedback as I write them. This collaborative authorship approach is inspired by the late David MacKay. I’d suggest you bookmark my book page and come back every couple of weeks for the latest instalment!

Happy Birthday FIPR!

On May 29th there will be a lively debate in Cambridge between people from NGOs and GCHQ, academia and Deepmind, the press and the Cabinet Office. Should governments be able to break the encryption on our phones? Are we entitled to any privacy for our health and social care records? And what can be done about fake news? If the Internet’s going to be censored, who do we trust to do it?

The occasion is the 20th birthday of the Foundation for Information Policy Research, which was launched on May 29th 1998 to campaign against what became the Regulation of Investigatory Powers Act. Tony Blair wanted to be able to treat all URLs as traffic data and collect everyone’s browsing history without a warrant; we fought back, and our “big browser” amendment defined traffic data to be only that part of the URL needed to identify the server. That set the boundary. Since then, FIPR has engaged in research and lobbying on export control, censorship, health privacy, electronic voting and much else.

After twenty years it’s time to take stock. It’s remarkable how little the debate has shifted despite everything moving online. The police and spooks still claim they need to break encryption but still can’t support that with real evidence. Health administrators still want to sell our medical records to drug companies without our consent. Governments still can’t get it together to police cybercrime, but want to censor the Internet for all sorts of other reasons. Laws around what can be said or sold online – around copyright, pornography and even election campaign funding – are still tussle spaces, only now the big beasts are Google and Facebook rather than the copyright lobby.

A historical perspective might perhaps be of some value in guiding future debates on policy. If you’d like to join in the discussion, book your free ticket here.

What Goes Around Comes Around

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.

Manifestos and tech

The papers went to town yesterday on the Conservative manifesto but missed some interesting bits.

First, no-one seems to have noticed that the smart meter programme is being quietly put to death. We read on page 60 that everyone will be offered a smart meter by 2020. So a mandatory national programme has become voluntary, just like that. Regular readers of this blog will recall that the programme was sold in 2008 by Ed Milliband using a dishonest impact assessment, yet all the parties backed it after 2010, leaving no-one to point out that it was going to cost us all a fortune and never save any carbon. May says she wants to reduce energy costs; this was surely a no-brainer.

That was the good news for England. The good news for friends in rural Scotland is high-speed broadband for all by 2020. But there are some rather weird things in there too.

What on earth is “the right of businesses to insist on a digital signature”? Digital signatures are very 1998, and we already have the electronic signature directive. From whom will businesses be able to insist on a signature, and if I’m one of the legislated victims, how much do I have to pay to buy the apparatus?

All digital businesses will have “to support new digital proofs of identification”. That presumably means forcing firms to use Verify, a dysfunctional online authentication service whose roots lie in Blair’s obsession with identity. If a newspaper currently identifies its subscribers via a proprietary logon, will they have to offer Verify as an option? Will it have to be the only option, displacing Facebook and Twitter? The manifesto also says that local government will have to use Verify; and elsewhere that councils must publish planning applications and bus routes “without the hassle and delay that currently exists.” OK, so some councils could so with more competent webmasters, but don’t worry: “hundreds of leaders from the world of tech can come into government to help deliver better public services.”

The Land Registry, the Ordnance Survey and other quangos that do geography (our leader’s degree subject) will all band together to create the largest open repository of land data in the world. So where will the Ordnance Survey get its money from then? That small question killed the same idea in 2010 after Tim Berners-Lee sold it to Cameron.

There will be a levy on social media companies, like on gambling companies, to support awareness and preventive activity. And they must not direct users, even unintentionally, to hate speech. So will Facebook be fined whenever they let users like a xenophobic article in the Daily Mail?

No doubt in view of the delicacy of such regulatory decisions, Leveson II is killed; there will be a Data Use and Ethics Commission instead. It will advise regulators and develop the principles and rules that will give people confidence their data are being handled properly. Wow. We now have the Charter of Fundamental Rights to give us principles, the GDPR to give us rules, and the ECJ to hammer out the case law. Now the People don’t have confidence in such experts we’re going to let the Prime Minister of the day appoint a different lot.

The next government will further strengthen cyber security standards for government and public services, so presumably all such services will have to use expensive networks such as the NHS-wide network from BT which will expect them to manage their own firewalls without telling them how to.

But don’t worry. It will become “as difficult to commit a crime digitally as it is physically”. There is text about working “with international law enforcement agencies to ensure perpetrators are brought to justice” but our local police force isn’t allowed to do anything effective about online accommodation fraud committed by a gang in Germany. They have to work through the NCA – who don’t care. The manifesto signals more of the same: the NCA will get to eat the SFO, which does crimes over £100m, leaving them even less interested in online crooks who steal a thousand pounds of deposit from dozens of students a year.

In fact there is no signal anywhere in the manifesto that May understands the impact of volume cybercrime, even though it’s now most of the property crime in the UK. She rather prefers to boast of the falling crime over the past seven years, as if it were her achievement as Home Secretary. The simple fact is that crime has been going online like everything else, and until 2015 the online part of it wasn’t recorded properly. This was not the doing of Theresa May, but of Margaret Hodge.

The manifesto rather seems to have been drafted in a geek-free room. And let’s not spoil the party by mentioning the impact that tight immigration targets will have on the IT industry, or for that matter on higher education. Perhaps they want us to hope that they don’t really mean that part of it, but perhaps we’d better make a plan to open a campus in India or Canada, just in case.

Video on Edge

John Brockman of Edge interviewed me in London in March. The video of the interview, and a transcript, are now available on the Edge website. Edge runs big interviews with several dozen scientists a year, with particular interest in people who do cross-disciplinary work. For me, the interaction of economics, psychology and engineering is one of the things that makes security so fascinating, as well as the creativity driven by adversarial behaviour.

The topics covered include the last thirty years of progress (of lack of it) in information security, from the early beginnings, through the crypto wars and crime moving online, to the economics of security. We talked about how cryptography can help less developed countries; about managing complexity in big projects; about how network effects lead firms to design insecure products; about whether big data can undermine democracy by empowering elites; and about how in a future world of intelligent things, security may become more about safety than anything else. Finally I talk about our current big project, the Cambridge Cybercrime Centre.

John runs a literary agency, and he’s worked on books by many of the scientists who feature on his site. This makes me wonder: on what topic should I write my next book?

“Do you see what I see?” ask Tor users, as a large number of websites reject them but accept non-Tor users

If you use an anonymity network such as Tor on a regular basis, you are probably familiar with various annoyances in your web browsing experience, ranging from pages saying “Access denied” to having to solve CAPTCHAs before continuing. Interestingly, these hurdles disappear if the same website is accessed without Tor. The growing trend of websites extending this kind of “differential treatment” to anonymous users undermines Tor’s overall utility, and adds a new dimension to the traditional threats to Tor (attacks on user privacy, or governments blocking access to Tor). There is plenty of anecdotal evidence about Tor users experiencing difficulties in browsing the web, for example the user-reported catalog of services blocking Tor. However, we don’t have sufficient detail about the problem to answer deeper questions like: how prevalent is differential treatment of Tor on the web; are there any centralized players with Tor-unfriendly policies that have a magnified effect on the browsing experience of Tor users; can we identify patterns in where these Tor-unfriendly websites are hosted (or located), and so forth.

Today we present our paper on this topic: “Do You See What I See? Differential Treatment of Anonymous Users” at the Network and Distributed System Security Symposium (NDSS). Together with researchers from the University of Cambridge, University College London, University of California, Berkeley and International Computer Science Institute (Berkeley), we conducted comprehensive network measurements to shed light on websites that block Tor. At the network layer, we scanned the entire IPv4 address space on port 80 from Tor exit nodes. At the application layer, we fetched the homepage from the most popular 1,000 websites (according to Alexa) from all Tor exit nodes. We compared these measurements with a baseline from non-Tor control measurements, and uncover significant evidence of Tor blocking. We estimate that at least 1.3 million IP addresses that would otherwise allow a TCP handshake on port 80 block the handshake if it originates from a Tor exit node. We also show that at least 3.67% of the most popular 1,000 websites block Tor users at the application layer.

Continue reading “Do you see what I see?” ask Tor users, as a large number of websites reject them but accept non-Tor users

Can we crowdsource trust?

Your browser contains a few hundred root certificates. Many of them were put there by governments; two (Verisign and Comodo) are there because so many merchants trust them that they’ve become ‘too big to fail’. This is a bit like where people buy the platform with the most software – a pattern of behaviour that let IBM and then Microsoft dominate our industry in turn. But this is not how trust should work; it leads to many failures, some of them invisible.

What’s missing is a mechanism where trust derives from users, rather than from vendors, merchants or states. After all, the power of a religion stems from the people who believe in it, not from the government. Entities with godlike powers that are foisted on us by others and can work silently against us are not gods, but demons. What can we do to exorcise them?

Do You Believe in Tinker Bell? The Social Externalities of Trust explores how we can crowdsource trust. Tor bridges help censorship victims access the Internet freely, and there are not enough of them. We want to motivate lots of people to provide them, and the best providers are simply those who help the most victims. So trust should flow from the support of the users, and it should be hard for powerful third parties to pervert. Perhaps a useful mascot is Tinker Bell, the fairy in Peter Pan, whose power waxes and wanes with the number of children who believe in her.