The website, DataGenetics, often displays quirky or amusing analyses for the enjoyment of viewers. The blogposts found here are often used to communicate powerful computer science theories or problems in compelling and easily accessible mediums. One that I particularly enjoyed was about Pin Numbers and their predictability. The visualization that you see above is a heat map of almost 3.4 million 4 digit passwords that he found by executing some SQL injection.
The heat map is one of several visualizations that he uses to analyze the problem and then educate his audience on how best to select a Pin number. I liked the heat map the best because it displays the serious lack of balance in Pin numbers that exist. Over 25% of all pin numbers could be guessed with only 20 combinations!
The heat map I attached shows the number of first two digit combinations on the x axis and number of second two digit combinations on the y axis. So at the bottom left is the Pin ‘0000’ and the top right is ‘9999.’ This heat map quite ably demonstrates the lack of spread among Pin numbers, and his box around the high concentration of numbers in the bottom left shows how easy it could be for a criminal to make an educated guess at people’s Pin Numbers.