Privacy Challenges

[vivian maxine]

Did you see this article in Science Daily?

http://www.sciencedaily.com/releases/20 ... ce+News%29

Let someone get ahold of just four of your purchase receipts and chances are 94% that he can figure out your credit card number.

Anyone surprised?

[Rilx]

Did you see this article in Science Daily?

http://www.sciencedaily.com/releases/20 ... ce+News%29

Let someone get ahold of just four of your purchase receipts and chances are 94% that he can figure out your credit card number.

Vivian, that's not what the article is about. As the article says, "just four fairly vague pieces of information -- the dates and locations of four purchases -- are enough to identify 90 percent of the people in a data set recording three months of credit-card transactions by 1.1 million users".

It means that four of your purchase receipts are enough to identify your behavior so that your other purchase receipts can be found amongst receipts of 1.1 million users. Four receipts are enough to identify 90% of users (by different behavior), five identify practically everyone.

So predictable we are. Modern fortune tellers don't need crystal spheres or tea leaves. They don't look in your hand; they look in your shopping bag.

[vivian maxine]

Sorry if I am misreading it but there is this:

So the MIT researchers also examined the effects of coarsening the data -- intentionally making it less precise, in the hope of preserving privacy while still enabling useful analysis. That makes identifying individuals more difficult, but not at a very encouraging rate. Even if the data set characterized each purchase as having taken place sometime in the span of a week at one of 150 stores in the same general areas, four purchases (with 50 percent uncertainty about price) would still be enough to identify more than 70 percent of users.

Nonetheless, de Montjoye and Pentland remain adamant that socially beneficial uses of big data should be pursued. "Sandy and I do really believe that this data has great potential and should be used," de Montjoye says. "We, however, need to be aware and account for the risks of re-identification."

if they can identify you, how much farther do you think they can go? There is no surety on the internet as many stores and banks have learned to their - and their customers' - sorrow.