Random prime number

Question

How do I quickly generate a random prime number, that is for sure 1024 bit long?

Answer 1

In PARI/GP:

randomprime([2^1023,2^1024])

If you'd like to do this in 'library mode'

#include 
// ...
randomprime(mkvec2(int2u(1023), int2u(1024)))