DarkDrop is a ZK privacy protocol for unlinkable SOL transfers on Solana. Hand someone a claim code, they pull the funds — sender and receiver never linked on-chain. Built around a credit note architecture I designed: claim TX shows zero decoded amounts. Three modes: DIRECT, PRIVATE (gasless relayer), MAX PRIVACY (two-layer ZK). Live on devnet. 18 instructions, 3 ZK circuits, 5 audits with 0 critical / 0 high open. darkdrop.app