DID you know there is a number in existence that will get you arrested in America if you publish it on a website or write it down?

Even having it scribbled on series of post-it notes could land you in some serious hot water with the law.

How could you be breaking the law by having a number in my possession you ask?

It all has to do with encryption and the Digital Millennium Copyright Act, which criminalised the production and dissemination of tools used to circumvent copyright measures.

Essentially, the prime number can be used to decrypt digital copyright protections on DVDs so people can download the content.

The reasoning behind the number is slightly convoluted, but thankfully YouTube channel Wendoverproductions broke things down in a video piece on the number earlier this week.

It all has to do with cryptology and prime numbers.

“There are an infinite number of primes as there is an infinite number of numbers, but it just takes an enormous amount of computing power to find these primes,” the video explains.

Why does that matter?

Encrypted data uses prime numbers with thousands of digits.

When logging onto something like your bank account your computer will send a number — known as the public key — to your bank’s server.

The bank will then check if two of its prime own numbers — known as private keys — multiply to make a number matching your public key.

If they match, you gain access to your online banking.

While it sounds simple, these prime numbers are thousands upon thousands of digits.

“If you wanted to find the private key you would need a computer to factor the public key, which would take thousands of years,” the video explains.

“With the amount of money it would take to actually set up a computer system that could factor the primes, it’s just not worth it.”

So the bigger the prime number, the more secure something is.

“Our illegal number 8565078 and so on and so forth, is a prime number that is the source code that is used to decrypt the copyright encryption of DVDs,” the video explained.

“The copyright protection was used to stop people downloading or duplicating movies on their computer and with this number protection was rendered useless.

“Programs were created that allowed individuals to make bootleg copies of movies all because of this number. All the while, individuals were breaking the law not only by copying DVDs, but also by just being in possession of this number.”