Circuit (ZK Circuit)
Also known as: ZK Constraint System, Proof Circuit, Zero-Knowledge Circuit
A computational structure used in zero-knowledge proofs to verify logic without revealing underlying data.
A ZK circuit is a representation of a computation expressed as arithmetic constraints, used to generate and verify zero-knowledge proofs. These circuits allow a prover to demonstrate knowledge of a certain value or that a computation is correct—without revealing the inputs. ZK circuits are central to privacy-preserving technologies and scalability solutions like zk-SNARKs and zk-STARKs. Developers build circuits using domain-specific languages (DSLs) such as Circom, Noir, or Halo2. Circuit efficiency directly affects proof size, generation time, and compatibility with Layer 1 blockchains.