As a few people have enquired but nobody's answered . . .
Prime numbers are useful for a few things but the one I know a bit about is encryption and digital signatures.
Most modern day (digital) encryption algorithms use large prime numbers because of their various properties.
By using modular arithmetic and prime numbers as keys, strong encryptions can be formed because prime numbers are very hard to factorise. (They use large numbers don't forget)
You'll probably find that a lot of the digital encryptions and signatures that you use on your computer either by compressing (and encrypting) files, using https, certificates of authority as well as others will use prime number theory as part of their algorithm.
Hope this was some help.
Slashdot Mirror
As a few people have enquired but nobody's answered . . . Prime numbers are useful for a few things but the one I know a bit about is encryption and digital signatures. Most modern day (digital) encryption algorithms use large prime numbers because of their various properties. By using modular arithmetic and prime numbers as keys, strong encryptions can be formed because prime numbers are very hard to factorise. (They use large numbers don't forget) You'll probably find that a lot of the digital encryptions and signatures that you use on your computer either by compressing (and encrypting) files, using https, certificates of authority as well as others will use prime number theory as part of their algorithm. Hope this was some help.