Amazingly, your PIN is probably either 1234, or 1111. Am I right? If not, well done; you are among the 75% of people that don’t use one of these two numbers. But everyone else, which therefore includes 1 in 4 people reading this, has one of these two numbers as their PIN.
Most bank machines allow a couple of attempts to enter your PIN in case you mistype the first time. So two goes would be enough to try both 1234 and 1111 with a 25% chance of hitting the jackpot.
Other common combinations include simple number patterns such as 4444 or 1212. Dates of birth figure regularly, so if you do use your date of birth, your PIN is more likely to be compromised if you keep other identification containing your date of birth in the same place as your credit cards.
However there is some good news. There are 10,000 potential combinations for a 4 digit PIN. So any PIN has a 1 in 10,000 chance of being guessed randomly. But because so many people choose one of the obvious number patterns, that means that the thousands of patternless number combinations are shared out thinly among the rest of the card holders. So for example, someone using 8398 or 6793 is sharing their PIN with around only 0.001% of other card holders, or 1 in 100,000.
So although your odds of any number being cracked randomly would still be 1 in 10,000, the important word here is ‘randomly’. The fact is that criminals and hackers know the most popular numbers and don’t always try randomly; they can save time and increase the chances of success by trying the common PINs first.
So when choosing your PIN, it’s probably better to choose a number that is likely to be shared with closer to 1 in 100,000 than 1 in 4 people!