zk-SNARK
A compact zero-knowledge proof that's fast to verify — the cryptography powering many privacy coins and zk-rollups.
A zk-SNARK (Zero-Knowledge Succinct Non-interactive Argument of Knowledge) is a specific form of zero-knowledge proof that is succinct (tiny and fast to verify, regardless of the computation’s size) and non-interactive (the prover sends one proof, no back-and-forth). These properties make it practical for blockchains, where cheap verification is essential.
zk-SNARKs power privacy coins like Zcash (shielding transaction details) and many zk-rollups (proving batch validity). Their historical drawback was needing a “trusted setup” — a one-time ceremony that, if compromised, could allow undetectable fake proofs — which newer schemes and zk-STARKs avoid. zk-SNARKs are among the most consequential cryptographic tools deployed in crypto’s second decade.