Passcodes Prove Predictable

mikejuk writes "Research reveals something we all suspected but couldn't prove — in a four digit pin the most popular first digit is one, the most popular second digit is two. Entropy only really kicks in on the third and fourth digits. What is more looking at the frequencies of four digit groups just 10 different passcodes would be enough to unlock one in seven iPhones!"

Comments

Benford's Law

[Bobtree]

Since people are likely to use passcodes based on real-world numbers so they can be remembered, perhaps Benford's law applies.

http://en.wikipedia.org/wiki/Benford's_law

Re:Entropy of passcode space

[elsurexiste]

I have said this once or twice in the past, but what the hell. :)

I did research on this subject and you, sir, nailed it. People don't choose numbers: they choose patterns, all the time. The most common passwords are, unsurprisingly, lines. A few are one or two repeating digits. People also have a fondness of diagonals and spirals, although this is noticeable when there are 16 or more buttons. That being said, I'm surprised that 5683 is so common.