Historical retrospective · Layer 2
Optimistic rollups made challenge periods a security primitive
Optimistic rollups post state claims that are treated as valid unless someone submits a successful fraud proof during a challenge window.
The model shifts the burden from proving every batch up front to making disputed execution challengeable.
It created a practical trade-off between proof cost, monitoring assumptions and withdrawal latency.
The challenge mechanism only works as intended when watchers, data and dispute contracts are available and correctly configured.
Primary source
This retrospective summarizes the source below in original language. The displayed year refers to the dated event, proposal or specification; it is not the article’s publication date. This is not investment, legal or security advice.