### Trivia

HardIn Your Average School Class There Is A 50% Chance Two People Share What?

**Answer: A Birthday**

In the field of probability theory, there is a problem known as the Birthday Paradox concerning the probability that in a selection of *N* randomly chosen people, some of them will share a birthday. This probability reaches 100 percent once you reach a sample size of 367 people (to account for the 366 potential days, including Feb. 29th, +1).

What’s fascinating, however, is how quickly the probability of sharing a birthday climbs. In a group of 23 people, around the size of a small class, the chances of two people sharing a birthday have already climbed to 50 percent. To get to 99 percent, you’d just need to gather two classrooms together. In a group of 57 people, there is a 99 percent chance that there is a common birthday.

While this might seem like something of a mathematical parlor trick, the math behind the Birthday Paradox has actually been successfully employed as a well known cryptographic attack, the Birthday Attack, which uses probabilistic modeling to reduce the complexity of cracking encryption hash functions.

### Trivia

HardWhich Of These Countries Has A Traditional Calendar With Dozens Of Microseasons?

### Trivia

HardLisa Simpson Is A Vegetarian Due To The Influence Of?

### Trivia

Very HardThe Holes In Swiss Cheese Are Caused By?

### Trivia

EasyThe Compound In Peppers That Gives Them Their Spicy Kick Is Called?

### Trivia

HardWhich Of Superman’s Powers Was Created At The Behest Of Animators?

### Trivia

EasyWhich Insects Are Used In Emergency Medicine?

### Trivia

HardWho Was The Only U.S. President To Hold A Patent?

### Trivia

HardBart Simpon’s Hit 90s Song “Do The Bartman” Was Ghost Written By None Other Than?

### Trivia

HardWhat Are Permanent and Unpatched Security Vulnerabilities Referred To As?