Category Archives: Social networks

We're hiring

We have a vacancy for a postdoc to work on the psychology of cybercrime and deception for two years from October. It might suit someone with a PhD in psychology or behavioural economics with a specialisation in deception, fraud or online crime; or a PhD in computer science with a strong interest in psychology, usability and security.

This is part of a cross-disciplinary project involving colleagues at Portsmouth, Newcastle and UCL. It will build on work we’ve been doing in the psychology of security over the past few years.

Security and Human Behaviour 2013

I’m liveblogging the Workshop on Security and Human Behaviour which is being held at USC in Los Angeles. The participants’ papers are here; for background, see the liveblogs for SHB 2008-12 which are linked here and here. Blog posts summarising the talks at the workshop sessions will appear as followups below. (Added: there is another liveblog by Vaibhav Garg.)

Current issues in payments (part 1)

In this first of a two or three part instalment. In them Laurent Simon and I comment on our impressions of David Birch’s Tomorrow’s Transactions Forum, which we attended thanks to Dave’s generosity.

NOTE: Although written in first person, what follows results from a combination of Laurent’s and my notes.

This was a two day event for a handful of guests to foster communication and networking. I appreciated the format.

After a brief introduction, the first day kicked off with my ever growing presentation on the origins of the cashless society (you can see it here ).

The following act was Tillman Bruett (UNCDF), who was involved in the drafting of The journey towards cash-lite (at least so say the acknowledgements).
Continue reading Current issues in payments (part 1)

Cloudy with a Chance of Privacy

Three Paper Thursday is an experimental new feature in which we highlight research that group members find interesting.

When new technologies become popular, we privacy people are sometimes miffed that nobody asked for our opinions during the design phase. Sometimes this leads us to make sweeping generalisations such as “only use the Cloud for things you don’t care about protecting” or “Facebook is only for people who don’t care about privacy.” We have long accused others of assuming that the real world is incompatible with privacy, but are we guilty of assuming the converse?

On this Three Paper Thursday, I’d like to highlight three short papers that challenge these zero-sum assumptions. Each is eight pages long and none requires a degree in mathematics to understand; I hope you enjoy them.

Continue reading Cloudy with a Chance of Privacy

Metrics for dynamic networks

There’s a huge literature on the properties of static or slowly-changing social networks, such as the pattern of friends on Facebook, but almost nothing on networks that change rapidly. But many networks of real interest are highly dynamic. Think of the patterns of human contact that can spread infectious disease; you might be breathed on by a hundred people a day in meetings, on public transport and even in the street. Yet if we were facing a flu pandemic, how could we measure whether the greatest spreading risk came from high-order static nodes, or from dynamic ones? Should we close the schools, or the Tube?

Today we unveiled a paper which proposes new metrics for centrality in dynamic networks. We wondered how we might measure networks where mobility is of the essence, such as the spread of plague in a medieval society where most people stay in their villages and infection is carried between them by a small number of merchants. We found we can model the effects of mobility on interaction by embedding a dynamic network in a larger time-ordered graph to which we can apply standard graph theory tools. This leads to dynamic definitions of centrality that extend the static definitions in a natural way and yet give us a much better handle on things than aggregate statistics can. I spoke about this work today at a local workshop on social networking, and the paper’s been accepted for Physical Review E. It’s joint work with Hyoungshick Kim.

Can we Fix Federated Authentication?

My paper Can We Fix the Security Economics of Federated Authentication? asks how we can deal with a world in which your mobile phone contains your credit cards, your driving license and even your car key. What happens when it gets stolen or infected?

Using one service to authenticate the users of another is an old dream but a terrible tar-pit. Recently it has become a game of pass-the-parcel: your newspaper authenticates you via your social networking site, which wants you to recover lost passwords by email, while your email provider wants to use your mobile phone and your phone company depends on your email account. The certification authorities on which online trust relies are open to coercion by governments – which would like us to use ID cards but are hopeless at making systems work. No-one even wants to answer the phone to help out a customer in distress. But as we move to a world of mobile wallets, in which your phone contains your credit cards and even your driving license, we’ll need a sound foundation that’s resilient to fraud and error, and usable by everyone. Where might this foundation be? I argue that there could be a quite surprising answer.

The paper describes some work I did on sabbatical at Google and will appear next week at the Security Protocols Workshop.