zk-SNARKs

A cryptographic proof system enabling one party to prove a statement's truth to another without revealing any underlying data beyond the statement's validity.

Zero-Knowledge Succinct Non-Interactive Arguments of Knowledge (zk-SNARKs) utilize advanced elliptic curve cryptography to compress complex computations into tiny, 288-byte proofs. These proofs allow protocols like Zcash and Ethereum Layer 2s (such as zkSync) to verify transactions in milliseconds while keeping sensitive inputs (like account balances or private keys) entirely off-chain. By decoupling the verification process from the data itself, zk-SNARKs provide the mathematical backbone for private, scalable decentralized systems.

https://z.cash/learn/what-are-zk-snarks/