Layer 2, rollups and zero knowledge

Why it matters

Users can inherit some base-layer security while accepting new sequencer, bridge, proof-system, upgrade and data-availability risks.

What moves off the base layer

A rollup can compress many state transitions into a smaller base-layer footprint. A sequencer may order transactions quickly, while final settlement and forced-exit rights depend on contracts and published data.

Lower fees are produced by batching and different resource assumptions, not by making computation free.

Optimistic and validity proofs

Optimistic rollups treat a submitted result as valid unless challenged with evidence during a defined window. Validity rollups submit a cryptographic proof that the transition followed the encoded rules.

Both designs rely on contract correctness, upgrade governance and access to the data needed to reconstruct or challenge state.

Zero knowledge is not one promise

A zero-knowledge proof can establish that a statement is true without exposing all underlying inputs. A ZK rollup may use that property for compact verification while transaction details remain public.

Privacy depends on the full protocol, data publication and application design—not the letters ZK in a product name.

The bridge and exit test

Ask who controls upgrades and sequencing, whether users can force inclusion or exit, how long withdrawals take, where data is stored and what happens if operators disappear.

A token moved through a third-party bridge may add a separate security model beyond the rollup's canonical contracts.