Category Archives: Privacy technology

Anonymous communication, data protection

Security Protocols 2015

I’m at the 23rd Security Protocols Workshop, whose theme this year is is information security in fiction and in fact. Engineering is often inspired by fiction, and vice versa; what might we learn from this?

I will try to liveblog the talks in followups to this post.

Can we have medical privacy, cloud computing and genomics all at the same time?

Today sees the publication of a report I helped to write for the Nuffield Bioethics Council on what happens to medical ethics in a world of cloud-based medical records and pervasive genomics.

As the information we gave to our doctors in private to help them treat us is now collected and treated as an industrial raw material, there has been scandal after scandal. From failures of anonymisation through unethical sales to the catastrophe, things just seem to get worse. Where is it all going, and what must a medical data user do to behave ethically?

We put forward four principles. First, respect persons; do not treat their confidential data like were coal or bauxite. Second, respect established human-rights and data-protection law, rather than trying to find ways round it. Third, consult people who’ll be affected or who have morally relevant interests. And fourth, tell them what you’ve done – including errors and security breaches.

The collection, linking and use of data in biomedical research and health care: ethical issues took over a year to write. Our working group came from the medical profession, academics, insurers and drug companies. We had lots of arguments. But it taught us a lot, and we hope it will lead to a more informed debate on some very important issues. And since medicine is the canary in the mine, we hope that the privacy lessons can be of value elsewhere – from consumer data to law enforcement and human rights.

Financial Cryptography 2015

I will be trying to liveblog Financial Cryptography 2015.

The opening keynote was by Gavin Andresen, chief scientist of the Bitcoin Foundation, and his title was “What Satoshi didn’t know.” The main unknown six years ago when bitcoin launched was whether it would bootstrap; Satoshi thought it might be used as a spam filter or a practical hashcash. In reality it was someone buying a couple of pizzas for 10,000 bitcoins. Another unknown when Gavin got involved in 2010 was whether it was legal; if you’d asked the SEC then they might have classified it as a Ponzi scheme, but now their alerts are about bitcoin being used in Ponzi schemes. The third thing was how annoying people can be on the Internet; people will abuse your system for fun if it’s popular. An example was penny flooding, where you send coins back and forth between your sybils all day long. Gavin invented “proof of stake”; in its early form it meant prioritising payers who turn over coins less frequently. The idea was that scarcity plus utility equals value; in addition to the bitcoins themselves, another scarce resources emerges as the old, unspent transaction outputs (UTXOs). Perhaps these could be used for further DoS attack prevention or a pseudonymous identity anchor.

It’s not even clear that Satoshi is or was a cryptographer; he used only ECC / ECDSA, hashes and SSL (naively), he didn’t bother compressing public keys, and comments suggest he wasn’t up on the latest crypto research. In addition, the rules for letting transactions into the chain are simple; there’s no subtlety about transaction meaning, which is mixed up with validation and transaction fees; a programming-languages guru would have done things differently. Bitcoin now allows hashes of redemption scripts, so that the script doesn’t have to be disclosed upfront. Another recent innovation is using invertible Bloom lookup tables (IBLTs) to transmit expected differences rather than transmitting all transactions over the network twice. Also, since 2009 we have FHE, NIZLPs and SNARKs from the crypto research folks; the things on which we still need more research include pseudonymous identity, practical privacy, mining scalability, probabilistic transaction checking, and whether we can use streaming algorithms. In questions, Gavin remarked that regulators rather like the idea that there was a public record of all transactions; they might be more negative if it were completely anonymous. In the future, only recent transactions will be universally available; if you want the old stuff you’ll have to store it. Upgrading is hard though; Gavin’s big task this year is to increase the block size. Getting everyone in the world to update their software at once is not trivial. People say: “Why do you have to fix the software? Isn’t bitcoin done?”

I’ll try to blog the refereed talks in comments to this post.

Our Christmas message for troublemakers: how to do anonymity in the real world

On the 5th of December I gave a talk at a journalists’ conference on what tradecraft means in the post-Snowden world. How can a journalist, or for that matter an MP or an academic, protect a whistleblower from being identified even when MI5 and GCHQ start trying to figure out who in Whitehall you’ve been talking to? The video of my talk is now online here. There is also a TV interview I did later, which can be found here, while the other conference talks are here.



Privacy with technology: where do we go from here?

As part of the Royal Society Summer Science Exhibition 2014, I spoke at the panel session “Privacy with technology: where do we go from here?”, along with Ross Anderson, and Bashar Nuseibeh with Jon Crowcroft as chair.

The audio recording is available and some notes from the session are below.

The session started with brief presentations from each of the panel members. Ross spoke on the economics of surveillance and in particular network effects, the topic of his paper at WEIS 2014.

Bashar discussed the difficulties of requirements engineering, as eloquently described by Billy Connolly. These challenges are particularly acute when it comes to designing for privacy requirements, especially for wearable devices with their limited ability to communicate with users.

I described issues around surveillance on the Internet, whether by governments targeting human rights workers or advertisers targeting pregnant customers. I discussed how anonymous communication tools, such as Tor, can help defend against such surveillance.

Continue reading Privacy with technology: where do we go from here?

Post-Snowden: the economics of surveillance

After 9/11, we worked on the economics of security, in an attempt to bring back some rationality. Next followed the economics of privacy, which Alessandro Acquisti and others developed to explain why people interact with social media the way they do. A year after the Snowden revelations, it’s time to talk about the economics of surveillance.

In a new paper I discuss how information economics applies to the NSA and its allies, just as it applies to Google and Microsoft. The Snowden papers reveal that the modern world of signals intelligence exhibits strong network effects which cause surveillance platforms to behave much like operating systems or social networks. So while India used to be happy to buy warplanes from Russia (and they still do), they now share intelligence with the NSA as it has the bigger network. Networks also tend to merge, so we see the convergence of intelligence with law enforcement everywhere, from PRISM to the UK Communications Data Bill.

There is an interesting cultural split in that while the IT industry understands network effects extremely well, the international relations community pays almost no attention to it. So it’s not just a matter of the left coast thinking Snowden a whistleblower and the right coast thinking him a traitor; there is a real gap in the underlying conceptual analysis.

That is a shame. The global surveillance network that’s currently being built by the NSA, GCHQ and its collaborator agencies in dozens of countries may become a new international institution, like the World Bank or the United Nations, but more influential and rather harder to govern. And just as Britain’s imperial network of telegraph and telephone cables survived the demise of empire, so the global surveillance network may survive America’s pre-eminence. Mr Obama might care to stop and wonder whether the amount of privacy he extends to a farmer in the Punjab today might be correlated with with amount of privacy the ruler of China will extend to his grandchildren in fifty years’ time. What goes around, comes around.

Small earthquake, not many dead (yet)

The European Court of Justice decision in the Google case will have implications way beyond search engines. Regular readers of this blog will recall stories of banks hounding innocent people for money following payment disputes, and a favourite trick is to blacklist people with credit reference agencies, even while disputes are still in progress (or even after the bank has actually lost a court case). In the past, the Information Commissioner refused to do anything about this abuse, claiming that it’s the bank which is the data controller, not the credit agency. The court now confirms that this view was quite wrong. I have therefore written to the Information Commissioner inviting him to acknowledge this and to withdraw the guidance issued to the credit reference agencies by his predecessor.

I wonder what other information intermediaries will now have to revise their business models?

Latest health privacy scandal

Today I gave a talk at the Open Data Institute on a catastrophic failure of anonymity in medical research. Here’s the audio and video, and here are the slides.

Three weeks ago we made a formal complaint to the ICO about the Department of Health supplying a large amount of data to PA Consulting, who uploaded it to the Google cloud in defiance of NHS regulations on sending data abroad. This follows several other scandals over NHS chiefs claiming that hospital episode statistics data are anonymous and selling it to third parties, when it is nothing of the kind.

Yesterday the Department of Health disclosed its Register of Approved Data Releases which shows that many organisations in both the public and private sectors have been supplied with HES data over the past year. It’s amazing how many of them are marked “non sensitive”: even number 408, where Imperial College got data with the with HESID (which includes postcode or NHS number), date of birth, home address, and GP practice. How officials can maintain that such data does not identify individuals is beyond me.