[tradedash]

Thanks for the link. I'll look into it!

> you can easily adjust the difficulty.

For Prime Factorization for instance, which like you say, isn't even NP-complete. You can easily adjust the difficulty by increasing the size of the number in question.

[JD557]

I'm not sure if that's completely true for prime factorization. There are numbers that are larger, yet easier to factorize.

For example, I think that a power of two, like 1024, is much faster to factorize than, let's say, 1001 (71113). (I'm not quite sure this example is true)

Here's a more detailed description: https://mathoverflow.net/questions/249266/classes-of-numbers...