Study Reveals It Takes Just Four Card Purchases to Identify Us
Friday, 13 February 2015
Researchers have found that as few as four card purchases can be used to identify almost anyone, with this being true for 99% of the population.
The study, which was undertaken by the Massachusetts Institute of Technology and their colleagues at Aarhus University in Denmark, analysed 3 months of credit card data from 1.1 million people who lived in an unidentified first world country.
Pieces of information, such as where individuals bought coffee, or visits to their favourite clothing store were enough to identify most people, making credit cards just as reliable as mobile phone records at identifying someone.
"Even data sets that provide coarse information at any or all of the dimensions provide little anonymity," said Yves-Alexandre de Montjoye, who headed up the study.
The study also found that even with some of the more specific data stripped, including things such as the general location of where a purchase was made rather than a specific shop, or increasing the amount of data looked at from 1 to 15 days, it was still fairly easy to identify people from just a few additional data points.
Women were found to be far more easy to identify than men, as their shopping behaviour resulting in more distinctive patterns. They also found that people with higher incomes were far easier to identify than those of lower income, this again being due to more distinct patterns in their shopping behaviour.
The researchers concluded their study by calling for more advanced technologies that better protected data, making purchases more anonymous than they are now.