Glossary
ZK Rollup
A Layer-2 that bundles transactions off-chain and proves their validity to L1 with a succinct zero-knowledge proof, allowing instant trust-minimized withdrawals.
A ZK (zero-knowledge) rollup executes transactions off-chain and generates a cryptographic proof that the state transition was correct. The L1 contract verifies the proof and updates the canonical state in a single transaction.
Unlike an optimistic rollup, ZK rollups don't need a multi-day challenge window: validity is established up front, so withdrawals can settle as soon as the next proof is posted. The cost is heavier proving — historically very expensive, now competitive thanks to specialized circuits and hardware.