3 Commits

Author	SHA1	Message	Date
Jesse Posner	b508e5dd9b	ecdsa_adaptor: add support for proof of discrete logarithm equality ... This commit adds proving and verification functions for discrete logarithm equality. From the spec (https://github.com/discreetlogcontracts/dlcspecs/pull/114): "As part of the ECDSA adaptor signature a proof of discrete logarithm equality must be provided. This is a proof that the discrete logarithm of some X to the standard base G is the same as the discrete logarithm of some Z to the base Y. This proof can be constructed by using equality composition on two Sigma protocols proving knowledge of the discrete logarithm between both pairs of points. In other words the prover proves knowledge of a such that X = a * G and b such that Z = b * Y and that a = b. We make the resulting Sigma protocol non-interactive by applying the Fiat-Shamir transformation with SHA256 as the challenge hash."	2021-03-16 16:13:34 -07:00
Jesse Posner	d8f336564f	ecdsa_adaptor: add nonce function and tags ... This commit adds a nonce function that will be used by default for ECDSA adaptor signatures. This nonce function is similar to secp256k1_nonce_function_hardened except it uses the compressed 33-byte encoding for the pubkey argument. We need 33 bytes instead of 32 because, unlike with BIP-340, an ECDSA X-coordinate alone is not sufficient to disambiguate the Y-coordinate.	2021-03-16 16:13:34 -07:00
Jesse Posner	654cd633f5	ecdsa_adaptor: initialize project ... This commit adds the foundational configuration and building scripts and an initial structure for the project.	2021-03-16 16:13:31 -07:00