zkRollup

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Zero-knowledge rollup (zkRollup) is a layer 2 scaling solution that increases throughput on Ethereum Mainnet by moving computation and state-storage off-chain. Along with the high gas and the slow problem of Ethereum, zkRollup is recognized as the best scaling solution for Ethereum to fix. It is as secure as Ethereum and has the shortest finalizing time compared to all other Layer 2 solutions such as State Channels and Plasma.

How Fox Tech stands out?

The basic idea of zkRollup is to aggregate a huge number of transactions into one Rollup block and generate a succinct proof for the block off-chain. The smart contract on Layer 1 only needs to verify the proof and apply the updated state directly without re-executing those transactions. This can help save the gas fee by an order of magnitude since proof verification is much cheaper than re-executing computations. Besides, data compression also does make an additional contribution to the saving which only keeps a minimum of on-chain data for verification. With our Fox solution, we are able to save another 50% gas fee from Ring’s eternal on-chain data service.

Fox Tech uses Validity Proofs to provide proof that state transitions are correct. A block contains a value representing the L2 state only if the L2 state is correct. Thus some representations of off-chain computations are sent to smart contracts. The smart contract will update the blockchain with this new value only after it has been verified correctly. The main advantage of Proof of Validity is that the blockchain will always reflect the correct L2 state and the new state can be immediately relied upon and used. However, the main drawback is that not only are the transitions controversial, but each state transition requires proof, which then affects scalability. Therefore, we use zk-FOAKs to solve the scalability under Validity Proofs.

Please refer below for more information about zk-FOAKs Overview.