What is KIP-16 and how does ZK proof verification work in Kaspa?

KIP-16 adds zero-knowledge (ZK) proof verification as a consensus-level opcode in Kaspa. A ZK proof is a cryptographic technique that lets one party prove a statement is true without revealing the underlying data. KIP-16 uses an extensible tag-based dispatch system where each tag maps to a different proof system; the initial implementation supports two RISC Zero proof types — Groth16 for compact proofs and Succinct STARKs for quantum-resistant proofs. The design explicitly allows new proof systems to be added via new tags without modifying the core opcode, so the protocol can adopt future cryptographic advances without requiring another hardfork.