Random prime number

Question

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

Answer 1

1. Generate 1024 random bits. Use a random source that is strong enough for your intended purpose.

2. Set the highest and lowest bits to 1. This makes sure there are no leading zeros (the prime candidate is big enough) and it is not an even number (definitely not prime).

3. Test for primality. If it's not a prime, go back to 1.

Alternatively, use a library function that generates primes for you.