what is the actual real-world application of prime numbers? Or is it just a math concept that’s neat to see and figure out but doesn’t have any actual use case?

Question

I read that they have some uses within online encryption, but to be honest I never really thought about why we learned them in school until this morning.

In: 20

Answer 1

One of the key tenets that makes modern cryptography work is that [prime factorization](https://en.wikipedia.org/wiki/Integer_factorization) of a number takes a long time. Multiplying two large prime numbers together is very easy. But doing the reverse – taking a very large number and trying to figure out what two numbers you used to multiply them together – is difficult. This is leveraged in many cryptographic schemes like RSA.