Mapping a Secret Scalar Value between Elliptic Curve Groups [broken]
This document outlines a method to map a secret scalar value x
from one elliptic curve group (secp256k1) to another elliptic curve group (a pairing-friendly curve).
This method leverages a variation of the Schnorr signature scheme to prove that the same secret scalar is used in both groups without revealing the value of x
.
This approach can be useful in applications where compatibility with different cryptographic groups is required. For example, in the context of using the Lightning Network to purchase in a PTLC a key to be used with pairing-based cryptography. In general, it is interesting for Adaptor Signatures, Scriptless Scripts, and Discreet Log Contracts.