Brian Scott

Why did the US ban this number in 2001? It sounds insane, but 25 years ago, the Motion Picture Association of America was genuinely trying to delete this number from the internet. You see, back in 1999, a teenager in Norway named Jon Lech Johansen wrote a piece of code called DeCSS. It cracked CSS, the encryption on DVDs. Suddenly, anyone could copy a movie with the click of a button. It was a nightmare for the movie studios. They went nuclear. They sued the hacker magazine 2600: The Hacker Quarterly. They threatened Slashdot, and their lawyers fired out cease-and-desist letters to anyone hosting the code. They called it a digital burglary tool. But the internet found a loophole. A computer scientist named Phil Carmody realized that computer code is just binary ones and zeros. And you can treat that string of binary as a single number. That way, you get a really, really big integer—which is the illegal code. But Carmody knew that just finding any number wasn’t going to be enough, because the government could still ban a random number. So he needed a number that science would be forced to protect. He needed a prime number. You see, the University of Tennessee maintains a prestigious academic database called the Prime Pages. It records the 5,000 largest known prime numbers. Carmody realized that if he could turn the illegal code into a record-breaking prime number, the university would have to publish it. His first attempt was 1,401 digits long. It was prime, but too small. It didn’t crack the top 5,000 list. It wasn’t mathematically interesting enough to save. So, he hacked the math. Use this formula: K × 256^N + B Now, K is the illegal code part. 256^N is the mathematical equivalent of adding useless zeros at the end—like making a book longer by adding blank pages. It doesn’t change the actual content inside. So, he kept adding “blank pages,” shifting the number, until he hit a mathematical jackpot—a 1,959-digit monster. This wasn’t just illegal code anymore. It became the 10th largest ECP prime number ever discovered at the time. It was checkmate. The number was immediately added to the university database. For the MPAA to ban the code now, they would have to order a university to delete a scientific record. You can’t censor mathematics.