As Tezos scales up through Etherlink and Tezlink, it will eventually have to rely on the Data Availability Layer (DAL) to ensure enough transaction data can be published per second.
However, the DAL operates with a short delay before new data can be confirmed available on Layer 1—the attestation lag—to allow time for the data to propagate across the DAL network.
This can impact certain Layer 2 features that rely on Layer 1 confirmation of data. A user-facing example is fast withdrawals on Etherlink, where the attestation lag would impact the speed of withdrawals.
In the upcoming protocol U proposal, we intend to rework the DAL attestation mechanism to minimize the attestation lag.
Note that from a user perspective, it only impacts certain withdrawal and bridging features. The DAL’s attestation lag has no impact on regular rollup transactions.
From fixed to dynamic
Currently, the protocol enforces a fixed delay to give the data time to propagate on the DAL network. In practice, propagation often happens faster, and in the protocol U proposal, we intend to include changes that make this delay dynamic.
Rather than wait until a fixed amount of time has passed, each baker publishes their attestation on Layer 1 as soon as they observe the new data on the DAL. Once 66% of the attesting power has attested to the new data, it is marked available, regardless of how much time has passed.
It means new data can be confirmed faster when the network is healthy and propagation is fast. Concretely, the attestation lag would be reduced from currently 11 blocks (66 seconds with the current 6-second Layer 1 block time) to an expected value of 2-3 blocks (12-18 seconds). Security and reward distribution rules remain unchanged.
For Etherlink, it improves the UX for DeFi, payments, and any other application benefitting from fast bridging and asset withdrawals.
Bottom Line
Dynamic DAL attestation lag aligns protocol behavior with actual network conditions, speeding up new DAL data confirmation when conditions are good.
It preserves safety, avoids unnecessary delays, and prepares Tezos for high‑performance applications with fast and frictionless interoperability.
