What is zk-SNARK?

A Zero-Knowledge Succinct Non-Interactive Argument of Knowledge (zk-SNARK) is a type of cryptographic proof used to ensure privacy on blockchain-based distributed ledger systems. It works by proving that one party is in possession of specific data without actually revealing the data to the network by using a secret key before the transaction is broadcasted. zk-SNARKS became prominent with Zcash, Monero, and other privacy-based blockchain protocols.