De-anonymization

De-anonymization is an important topic for anyone working with sensitive data, whether in the context of academic research, IT system design, or otherwise.

I remember a talk during a Massey Grand Rounds panel where a medical researcher explained how she could pick herself out from an ‘anonymous’ database of Ontarians, on the basis that her salary was public as an exact dollar figure, only people with her specific job had it, and she was the only woman in that position.

The more general idea is that by putting pieces together you may be able to identify somebody who someone else has made some effort to keep anonymous.

It’s a challenge when doing academic research and writing on social movements, when some subjects choose to be anonymous in publications. That means not just not sharing their name, but not sharing any information that could be used to identify them. That gets hard when you think about adversaries who might have access to other information (in an extreme case, governments with access to masses of information) or even just ordinary people who can combine information from multiple sources logically. The date of an event described in an anonymous quote might tell allow someone to look up where it happened online. Another quote in which a third party’s actions are described could be used to determine that the de-anonymization target wasn’t that person. And so on and on like the logical games on the LSAT or the intricacies of mole hunting.

Lee Ann Fujii wrote smart stuff about this, and about subject protection in research generally.

Author: Milan

In the spring of 2005, I graduated from the University of British Columbia with a degree in International Relations and a general focus in the area of environmental politics. In the fall of 2005, I began reading for an M.Phil in IR at Wadham College, Oxford. Outside school, I am very interested in photography, writing, and the outdoors. I am writing this blog to keep in touch with friends and family around the world, provide a more personal view of graduate student life in Oxford, and pass on some lessons I've learned here. View all posts by Milan