PIN analysis


“All credit card PIN numbers in the World leaked”

The body of the message simply said 0000 0001 0002 0003 0004 

The Data

I was able to find almost 3.4 million four digit passwords. Every single one of the of the 10,000 combinations of digits from 0000 through to9999 were represented in the dataset.

The most popular password is  1234  …
… it’s staggering how popular this password appears to be. Utterly staggering at the lack of imagination …
… nearly 11% of the 3.4 million passwords are  1234  !!!
The next most popular 4-digit PIN in use is  1111  with over 6% of passwords being this.

In third place is  0000  with almost 2%.

A table of the top 20 found passwords in shown at the right. A staggering 26.83% of all passwords could be guessed by attempting these 20 combinations!

(Statistically, with 10,000 possible combination, if passwords were uniformly randomly distributed, we would expect the these twenty passwords to account for just 0.2% of the total, not the 26.83% encountered)

Looking more closely at the top few records, all the usual suspects are present  1111   2222  3333  …  9999  as well as  1212  and (snigger)  6969 .

It’s not a surprise to see patterns like  1122  and  1313  occurring high up in the list, nor  4321  or 1010 .

2001  makes an appearance at #19.  1984  follows not far behind in position #26, and James Bond fans may be interested to know  0007  is found between the two of them in position #23 (another variant  0070  follows not much further behind at #28).

PIN Freq
#1 1234 10.713%
#2 1111 6.016%
#3 0000 1.881%
#4 1212 1.197%
#5 7777 0.745%
#6 1004 0.616%
#7 2000 0.613%
#8 4444 0.526%
#9 2222 0.516%
#10 6969 0.512%
#11 9999 0.451%
#12 3333 0.419%
#13 5555 0.395%
#14 6666 0.391%
#15 1122 0.366%
#16 1313 0.304%
#17 8888 0.303%
#18 4321 0.293%
#19 2001 0.290%
#20 1010 0.285%

The first “puzzling” password I encountered was  2580  in position #22. What is the significance of these digits? Why should so many people select this code to make it appear so high up the list?

Then I realized that  2580 is a straight down the middle of a telephone keypad!
(Interestingly, this is very compelling evidence confirming the hypothesis that a 4-digit password list is a great proxy for a PIN number database. If you look at the numeric keypad on a PC-keyboard you’ll see that 2580 is slightly more awkward to type on the PC than a phone because the order of keys on a keyboard is the inverted. Cash machines and other terminals that take credit cards use a phone style numeric pads. It appears that many people have an easy to type/remember PIN number for their credit card and are re-using the same four digits for their online passwords, where the “straight down the middle” mnemonic no longer applies).

(Another fascinating piece of trivia is that people seem to prefer even numbers over odd, and codes like  2468  occur higher than a odd number equivalent, such as  1357 ).

 

Source : http://www.datagenetics.com/blog/september32012/


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