Comment by MattPalmer1086
6 hours ago
Sure, you can't use built in multiplication, but it isn't a very big hurdle. Just use repeated squares, it's fairly trivial to implement. I've worked on software that did this on very low power mobile payment devices.
Repeated squares is a way to implement exponentiation, not multiplication.
Oops, yes, I meant exponentiation. Which you need (mod n) in RSA.