> For the complete documentation index, see [llms.txt](https://docs.transferchain.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.transferchain.io/core-concepts/cryptography/elliptic-curve.md).

# Elliptic-Curve

### Choice of an Elliptic Curve

The only restriction that the underlying proxy re-encryption scheme cryptosystem imposes on the choice of an elliptic curve is that it should generate a group of prime order, since we need to compute inverses modulo the order of this group. In the underlying setting of the proxy re-encryption scheme, we use the secp256k1 curve since it fulfills this latter requirement and is widely used in the blockchain ecosystem; we are exploring other curve choices that could improve performance.

![](/files/lOz76KLslhkNLourPYmR)