Multiplicative-to-additive conversion (MtA)

Threshold ECDSA protocols (GG18, CMP20) need to compute a product of two secrets without either party learning the other’s value. The MtA trick uses Paillier homomorphic encryption: one party encrypts its share, the other multiplies the ciphertext by an additive mask, and a zero-knowledge range proof keeps everything in bounds.

confium-crypto-vss ships the Paillier primitives (keygen, encryption, range proofs) used by the CMP20 and GG18 scheme crates. You rarely invoke MtA directly; it is listed here because it is the performance and security heart of threshold ECDSA.