Yes, but for crypto you only need to optimise for small "bignums". So performance is not satisfactory for larger stuff, at least not last time I looked. Which was a while ago.

I should add that crypto is a whole 'nuther ballgame. You often need your algorithms to not leak information. That often means going to pretty insane lengths to ensure that.

The standard in good crypto software is also so much more exacting. You don't want to be 99.9% sure it has no exploitable bugs. You want to be 99.999% sure.

I'm absolutely no kind of crypto expert. I'm a number theorist. In no way would bsdnt be suitable for use in crypto applications!