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87% of the U.S. Population are uniquely identified by {DOB, gender, zip}

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Re: 87% of the U.S. Population are uniquely identified by {DOB, gender, zip}

#81

Post by jmaygarden »

blahedo wrote: post #49
russell wrote: post #44

Earlier quoted context omitted.

I had to deal with the converse of the problem when I was working for a company that ran the vehicle smog checking for the state of Illinois. A driver's license id was composed of birthdate, sex, and some location information (I dont remember exactly what) for the reasons mentioned by jdp23 it worked quite well, except for identical twins, who had the same driver's license id. (Registrations ofter were processed by h…

> ...for the state of Illinois. A driver's license id was composed of birthdate, sex, and some location information.... It's worse than that: in Illinois the first four characters of your DL ID are your last name's soundex code.

The first four characters of my FL driver's license are a soundex code of my last name. So, this appears to be a common practice.

I always thought that part looked suspicious. Thanks for the tip.

Re: 87% of the U.S. Population are uniquely identified by {DOB, gender, zip}

#82

Post by dasil003 »

firemanx wrote: post #25
xxbondsxx wrote: post #23

Earlier quoted context omitted.

Birth location =/= mailing address zipcode. Babies are usually born in hospitals, and thus parents from many areas concentrate in one specific building. When you re-distribute these births out to their respective homes around the county, the zip code becomes much more important.

In towns like mine, however, 40,000 people share the same zip code with the hospital. I'm sure there are quite a few more town like mine throughout the US.

Okay, well let's do the math:

US pop in 2000: 280,000,000 — US births in 2000: 4,000,000 — US births per day: 10,958 — Fraction of US pop that 40,000 represents: 0.0001428 — Number of births per day for the 40,000: 1.56

That seems inline with the conclusion of the paper. See any mistakes?

Re: 87% of the U.S. Population are uniquely identified by {DOB, gender, zip}

#84

Post by giberson »

This is an interesting statistic for another reason aside from de-anonymization, particularly directory listing applications. A lot of web sites have url's to access the user's profile page by their username. For popular sites, it's always a rush to register "yourname" as a username so that you can get website.com/. Inevitably, your name gets registered by some one else and you're stuck picking a nick name or appending a randomized letter set to it.

I've been pondering a useful way to have /in a URL, so that everyone with that name can use the url containing it without collisions. Of course, I always end up with something like website.com/a3fx/. Which is arbitrary, and ugly. However, with this stat it seems we have something close to a non colliding, pretty, meaningful addressing scheme. Ie: website.com////, sure it's a bit long but it provides assurance you're getting who you think your getting.

Re: 87% of the U.S. Population are uniquely identified by {DOB, gender, zip}

#85

Post by greenyoda »

matthewsimon wrote: post #52
mikey_p wrote: post #2

While I find this fascinating, I'm sure this is old news to people in the business, like the people that run the grocery/chain store savings programs. What I'd be really interested to see is why this works, and what it tells us about distribution of population by zip code. I'd imagine the places where this doesn't work as well, are the most densely populated zip codes, where the likely hood of duplicates on the given…

> ... the most densely populated zip codes ... It turns out that zip codes aren't as populous as you might imagine. As of the Y2K census, only a dozen zip codes have over 100,000 residents -- 80% of all zip codes have less than 15,000 residents, with the median zip code at 2,500. (Source: http://www.census.gov/geo/www/gazetteer/places2k.html )

Some zip codes have zero residents -- a few large office buildings have their own zip codes, but nobody actually has a home address there. Examples: the Empire State Building, the Pentagon, the former World Trade Center, IRS tax processing centers.

Re: 87% of the U.S. Population are uniquely identified by {DOB, gender, zip}

#86

Post by natrius »

giberson wrote: post #84

This is an interesting statistic for another reason aside from de-anonymization, particularly directory listing applications. A lot of web sites have url's to access the user's profile page by their username. For popular sites, it's always a rush to register "yourname" as a username so that you can get website.com/ . Inevitably, your name gets registered by some one else and you're stuck picking a nick name or append…

A problem with that is that people move, so zip codes change. You could fix that by substituting artificial, user-chosen groupings for zip codes if you used enough of them to have a similar distribution. Users could pick a grouping based on their interests, and you could even keep the geographical aspect of it by treating them as "neighborhoods". People who play the stock market could choose WallStreet, science fiction fans could choose Area51, wine aficionados could choose NapaValley, and so on.

Re: 87% of the U.S. Population are uniquely identified by {DOB, gender, zip}

#88

Post by throw_away »

caf wrote: post #69
tokenadult wrote: post #56

Earlier quoted context omitted.

October 8th is actually in the top 100 of birthdates by frequency of births, according to the best data table I have seen on the subject. http://www.nytimes.com/2006/12/19/business/20leonhardt-table... Of course February 29th is dead last in frequency. Most early October birthdays are above the median in frequency.

Note the group of high rankings from 8-Sep, tailing off in early October - all those NYE babies ;)

also interesting is looking at the next lowest frequency dates-- all of them are clustered around major holidays:

365 12 25

364 1 1

363 12 24

362 1 2

361 7 4

360 12 26

359 11 28

358 11 27

357 11 26

356 1 3

355 10 31

354 12 23

353 11 25

352 11 24

Re: 87% of the U.S. Population are uniquely identified by {DOB, gender, zip}

#89

Post by glimcat »

jdp23 wrote: post #5

Here's some backstory, from the 1990s when the Massachusetts' Group Insurance Commission released "anonymized" health data: ''At the time GIC released the data, William Weld, then Governor of Massachusetts, assured the public that GIC had protected patient privacy by deleting identifiers. In response, then-graduate student Sweeney started hunting for the Governor’s hospital records in the GIC data. She knew that Gove…

Never underestimate the power of bored graduate students.

Re: 87% of the U.S. Population are uniquely identified by {DOB, gender, zip}

#90

Post by bobds »

delluminatus wrote: post #68
mbrubeck wrote: post #11

Earlier quoted context omitted.

The EFF has done some research on that question: https://panopticlick.eff.org/

Interesting -- using NoScript reduced my "bits of information" from 20 to 14. I would have expected it to increase the uniqueness of my browser.

They can get considerably less data if you don't have Javascript enabled.
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