Implementation of monero on other curves

Question

Are there any other implementations of curves in the Monero code (other than Curve25519)?

I'm asking because the code is very optimized to this curve (e.g. the multiplication in 8 when computing the stealthy address).

And, I'm trying to add some feature, but the field of the Edwards curve is not suitable for my needs.

Thanks.

Answer 1

There are two birationally equivalent variants of X25519, which are Curve25519 and Ed25519. Monero uses only Ed25519.

There might be performance reasons for using Curve25519 vs Ed25519 depending on whether you're doing variable base or double base scalar multiplication, but I can't think of a reason that Ed25519 would limit you functionally. Curves provide a trapdoor function, and you should be able to functionally achieve the same result with any curve.