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/