KZG Commitment

A polynomial commitment scheme (Kate–Zaverucha–Goldberg) that commits to a whole polynomial (and the data it encodes) in one small value and proves facts about it — like an evaluation at a point — with constant-size proofs and cheap verification, however large the data. It's the shared engine behind PLONK-style SNARKs, danksharding blobs, and verkle trees. The cost is a trusted setup (mitigated by large multi-party ceremonies) and reliance on elliptic-curve pairings that are not post-quantum secure.