Amazing to see so many major L2s now at stage 1. The next goal we should shoot for is, in my view, fast (<1h) withdrawal times, enabled by validity (aka ZK) proof systems. I consider this even more important than stage 2. Fast withdrawal times are important because waiting a week to withdraw is simply far too long for people, and even for intent-based bridging (eg. ERC-7683), the cost of capital becomes too high if the liquidity provider has to wait a week. This creates large incentives to instead use solutions with unacceptable trust assumptions (eg. multisigs/MPC) that undermine the whole point of having L2s instead of fully independent L1s. If we can reduce native withdrawal times to under 1h short term, and 12s medium term, then we can further cement the Ethereum L1 as the default place to issue assets, and the economic center of the Ethereum ecosystem. To do this, we need to move away from optimistic proof systems, which inherently require waiting multiple days to withdraw. Historically, ZK proof tech has been immature and expensive, which made optimistic proofs the smart and safe choice. But recently, this is changing rapidly. ethproofs.org/ is an excellent place to track the progress of ZK-EVM proofs, which have been improving rapidly. Formal verification on ZK proofs is also advancing. Earlier this year, I proposed a 2-of-3 ZK + OP + TEE proof system strategy that threads the needle between security, speed and maturity: ethereum-magicians.org/t/a-s… * 2 of 3 systems (ZK, OP) are trustless, so no single actor (incl TEE manufacturer or side channel attacker) can break the proof system by violating a trust assumption * 2 of 3 systems (ZK, TEE) are instant, so you get fast withdrawals in the normal case * 2 of 3 systems (TEE, OP) have been in production in various contexts for years This is one approach; perhaps people will opt to instead do ZK + ZK + OP tiebreak, or ZK + ZK + security council tiebreak. I have no strong opinions here, I care about the underlying goal, which is to be fast (in the normal case) and secure. With such proof systems, the only remaining bottleneck to fast settlement becomes the gas cost of submitting proofs onchain. This is why short term I say once per hour: if you try to submit a 500k+ gas ZK proof (or a 5m gas STARK) much more often, it adds a high additional cost. In the longer term, we can solve this with aggregation: N proofs from N rollups (plus txs from privacy-protocol users) can be replaced by a single proof that proves the validity of the N proofs. This becomes economical to submit once per slot, enabling the endgame: near-instant native cross-L2 asset movement through the L1. Let's work together to make this happen.

Why I used to prefer permissive licenses and now favor copyleft vitalik.eth.limo/general/202…