Vitalik Buterin, the founder of Ethereum has proposed a solution to build an ultra-secure blockchain. Commenting on the classic debate of optimistic rollups vs ZK rollups, Buterin proposed a hybrid model that can take the best of both worlds.
The Debate Between Rollups
Rollups are Layer 2 solutions that aim to improve the scalability of a blockchain. Rollups can combine a bunch of transactions into one and post the final state. Currently, at its best, Ethereum can handle around 20-30 TPS. Rollups can improve the speed of transactions multifold.
There are two major types of rollups: optimistic rollups and ZK rollups. Optimistic rollups have a pessimistic nature that believes all the transactions to be correct until proven otherwise. They combine all the transactions into one without checking their authenticity. Then, they allow a period for anyone to dispute the authenticity. On the other hand, ZK rollups check the authenticity of every transaction.
While ZK proofs are more secure, they are oftentimes expensive to generate. Vitalik Buterin attempts to solve this issue.
Vitalik’s Proposed Plan
Buterin’s plan takes the best of both worlds. He proposed to build a rollup that would combine optimistic rollups and ZK rollups. According to his plan, a blockchain would publish a block. Then the chain would wait for 24 hours to submit a challenge. If there is no challenge to the block, then a ZK-SNARK, which is a type of ZK proof, will be published.
If there is a challenge to the authenticity of any transaction, then the decision will be made by consulting between the optimistic rollup, zero knowledge rollup, and overall blockchain governance. Any disputes between optimistic rollup and ZK rollup will be solved by the governance.
Rollups are currently a very hot topic in the Ethereum ecosystem. Polygon just launched a zero-knowledge-based EVM that would be compatible with any smart contract that is also compatible with the Ethereum mainnet. Following Polygon’s announcement, Matter Labs And Scroll also announced their zkEVMs.