Spent hours mapping out the entire privacy landscape today. Here is a clean tiered framework to keep in your head. Tier S Monero | XMR: Privacy by default on every single transaction. Ring signatures + stealth addresses + RingCT. The upcoming FCMP++ upgrade brings mathematically proven untraceability. This is the gold standard. Zcash | ZEC: zk-SNARKs via Halo 2 with a shielded pool. 86.5% of all transactions are now protected. Backed by Naval, Winklevoss, Vitalik, and Grayscale. Tier A iExec | RLC: Leading secure computing. The only TEE provider on Arbitrum. Real products: Web3Mail, Privacy Pass, confidential DeFi. Railgun | RAIL: zk-SNARKs protecting DeFi directly on Ethereum L1. Integrated by the ETH Foundation. Aztec Network: Created PLONK. Building the first fully decentralized L2 for private smart contracts. Zama: Fully Homomorphic Encryption. First private stablecoin transfer on ETH. TFHE-rs library with over 1 million downloads. Starknet | STRK: Shielded balances and private transfers for any ERC-20. Quantum resistant and incredibly fast. Arcium | ARX: Native MPC encrypted computing on Solana. Private SPL tokens coming soon. Tier B Aleo | ALEO: Off-chain ZK computation. Private stablecoins from Circle and Paxos live on-chain. Miden: Full client-side proving and execution. Private contracts interacting with public ones. Dusk | DUSK: Building for regulated finance with auditable privacy. Fhenix: CoFHE is 50x faster than standard FHE, fully EVM compatible for private smart contracts. Inco Network: FHE + TEE + MPC layer composable with any EVM chain. Umbra | UMBRA: Privacy wallet on Solana using Arcium's MPC. Tier C Oasis | OASIS: Production-ready private EVM + ROFL for private AI (trustless AWS). Nym: Mixnet layer 0 hiding metadata. Real product: NymVPN. Nillion: Blind computation via MPC. Partnered with Meta on private AI. Secret Network | SCRT: Native private smart contracts, now pivoting hard to SecretAI. Firo | FIRO: Lelantus Spark (peer-reviewed ZK ...