Yes, there is definitely room for improvements. I just wanted to check if using bigints with minimal changes would be working. And I am actually surprised it does, since I was not able to find a gcd prox overloaded for BigInt (I was expecting to have to provide an implementation). Not sure what is being used there. Also, I I think in place addition and multiplication are not exported in bigints.
Regarding the usage of stint, I would guess the actual Telegram protocol might go beyond uint64 and might have a specific size that one can work with.
