Zero-Knowledge Proof (ZK Proof)
Cryptographic method proving knowledge without revealing the knowledge itself.
Zero-Knowledge Proof (ZK proof) is a cryptographic technique allowing one party (Prover) to prove to another (Verifier) that they know some information — without revealing the information itself.
Classic example: Proving you know a vault password without saying the password.
Applications in cryptocurrencies:
1. Transaction privacy: • Zcash (zk-SNARKs) — proves you have enough funds without revealing balance • Monero uses different approach (Ring Signatures + Stealth Address)
2. ZK-Rollups (scalability): • Thousands of transactions compressed into one ZK proof • Ethereum verifies only the proof (fast and cheap) instead of each transaction • zkSync, Starknet, Polygon zkEVM, Scroll
3. Identity without KYC: • Prove you're of age without revealing date of birth • Worldcoin attempts ZK human verification
zk-SNARKs vs zk-STARKs: