RSA cryptosystem

Why can't you just use any number for secret codes?

Imagine you want to send a secret message to a friend, like telling them to meet at the park, but you don't want anyone else to know.

Think of a secret code as a lock that only your friend has the key to. You use a special pair of numbers that are really hard to break apart, like a super tough puzzle. These numbers are called primes.

Example

You and your friend pick two numbers, 17 and 23, which are both primes. You multiply them to get 391, which is your public key. Only your friend knows the original numbers, so they can multiply them back to 391 and unlock your secret message.

Remember this

Using prime numbers makes it incredibly difficult for others to crack your secret code, ensuring your message stays private.

Text adapted from Wikipedia, licensed under CC BY-SA 4.0.

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