PLONK

PLONK is an advanced type of ZK-SNARK that allows for efficient, scalable, and universal verification of computations with a single setup for multiple proofs. PLONK is designed to address the limitations of the original ZK-SNARKs, where each circuit requires a process called the trusted setup. In this phase, a group of trusted individuals generates a set of initial parameters that are later used to create and verify proofs. While this process is essential for creating concise proofs, it raises potential security and transparency concerns because provers and verifiers must trust that the participants in the setup phase have acted correctly and without any malicious intent. 

PLONK addresses these challenges by requiring only a single universal trusted setup. This universal setup can be reused for any circuit, greatly reducing the complexity and potential risks associated with the trusted setup phase. Moreover, PLONK enhances the efficiency and flexibility of SNARK-based proof systems through the use of polynomial commitments, specifically Kate commitments. These commitments enable the verifier to check the validity of the proof without having to recompute the entire proof from scratch, thus improving both efficiency and security.

PLONK and its enhanced variations are implemented in some ZK-rollup and zkEVM protocols, including Polygon zkEVM.