Prime Numbers are of great interest to mathematicians for a variety of reasons. Primes also play a central role in the cryptographic systems which are used for computer security. Through the study of Prime Numbers it can be shown how much processing is required to crack an encryption code and thus to determine whether current security schemes are sufficiently secure. PrimeGrid is currently running several sub-projects: -Primegen: generating a public sequential prime number database (end phase). -Twin Prime Search: searching for gigantic twin primes of the form k*2n + 1 and k*2n - 1. -Cullen-Woodall Search: searching for mega primes of forms n*2n + 1 and n*2n - 1. -3*2^n-1 Search: searching for mega primes of the form 3*2n - 1. -Prime Sierpinski Project: helping Prime Sierpinski Project solve the Prime Sierpinski Problem. You can choose the projects you would like to run by going to the project preferences page.