>>47550
Dude, factoring prime numbers is hard. First, you have to write down “1”. That's the easy part. Then, you have to write down the number itself. That can be pretty exhausting.

>>47550
Are they trying to say that it takes computers two years to confirm that a number is prime? You do have to keep check every single prime number that is less than the one you are checking.

>>47553
>>47580
semi primes. finding the prime number that makes the semi prime is what encryption is about. semi primes have mountains of possible combinations that could have resulted the semi prime which is the key. this is especially so for massive semi primes made with massive prime numbers. this why why they are ALWAYS looking to find the next biggest prime number.

>>47580
you don't have to check every number. you can skip even numbers, multiples of 3, multiples of 5...

anyway, what the article probably meant to say was factoring the products of two large primes.

>>50355
Well duh that is why I said
>You do have to keep check every single prime number that is less than the one you are checking.
You would check every prime against the number you think is prime, it becomes not prime if it's divisible by one of the numbers you pick.

>>49379
Finding semi-primes is more difficult, since if the number is not semi-prime you have to make a little less than (number of primes smaller than the number you have)!

You can eliminate combinations that obviously won't yield the large number you have such as 2*2, but it still is a large amount of computations.

>>47580
It's a typo from lack of proofreading as OP said.
>You do have to keep check every single prime number that is less than the one you are checking.
This isn't true at all.

>>51678
Didn't know about that other stuff like the between 2 and srt(n) stuff, thanks for making me look it up.

>>53671
most commonly used are probabilistic primality tests e.g.
https://en.wikipedia.org/wiki/Baillie%E2%80%93PSW_primality_test