Why are primes important for encryption Why are primes so important? Why can't we just use a random number?
My guess is that it's because finding a random prime require more computing power, than finding a random number. Can anybody confirm this?
Primes are important because the security of many encryption algorithms are based on the fact that it is very fast to multiply two large prime numbers and get the result, while it is extremely computer-intensive to do the reverse. When you have a number which you know is the product of two primes, finding these two prime numbers is very hard. This problem is called prime factorization and finding an algorithm which does it fast is one of the unsolved problems of computer science.