"Anonymized" data really isn't—and here's why not
arstechnica.com
arstechnica.com
I'm one of the authors of the Netflix and social network de-anonymization papers referenced, and the author of http://33bits.org. I also had the pleasure of having many talks with law professor Paul Ohm over the technical aspects of his excellent paper (which another commenter has posted a link to.)
Paul's paper is a great example of people in the law community "getting it." (He happens to have a CS degree and is a hobbyist perl hacker!) We need more people like Paul, and we equally also need tech people who understand law and policy. I encourage everyone to give Paul's paper a quick read, gain awareness of the issues such why the current privacy laws are wrongheaded and what needs to be changed, and be on the look-out for ways to change things (as consumers, as tech influencers, as citizens). Cheers.
Have you heard of jump links? ;0)>
(The title comes from the factoid that 33 bits of information is enough to uniquely address any living person. After reading through a few practical examples I'm convinced: anonymity is an illusion.)
A close friend of mine, throughout over 5 years of college, shared one grocery store "club" card with all roommates and acquaintances, eventually totaling a couple dozen users.
The disincentives by the store to doing this, usually in the form of a bonus paid to the instant user at some predetermined spending level, were ineffective, since the group was one who would gladly pay $1 for a lottery ticket, and this was a bargain by comparison.
Personally, I routinely give bogus ZIP codes for any situation other than where I wish to receive mail.
The actual savings are nominal: spend $150, fill up w/ 20 gallons (the limit), and save what, $6.00? That's only 4%!
But wow, people have become much more serious about using their own cards. Participation must be near 100%.
confusing whether we're talking binary bits or unique pieces of information.
33 bits is presumably from the world population being < 2^33 (WolframAlpha puts world pop. at 6 Billion in 2007).
http://www.freedom-to-tinker.com/blog/paul
I couldn't get SSRN to cooperate; the download buttons just kept returning me to the abstract. BTW, Ohm himself admits SSRN has problems, in the comments of the post where he announces the paper.
http://www.freedom-to-tinker.com/blog/paul/anonymization-fai...