I know that being able to factor ~670/1024-bits isn't that impressive (overall). But the fact that it is possible to develop the software this far shows that it

I know that being able to factor ~670/1024-bits isn't that impressive (overall). But the fact that it is possible to develop the software this far shows that it's mainly a hardware problem. Enough parallelization into GPU cores with a significant system, and I think that cracking a 1024-bit key comes to less than a week.