ZK-Rollup Specification

Summary: ADI Chain is a ZK-Rollup that uses validity proofs to ensure that every action taken on the network is accurately recorded and submitted to the Ethereum L1 chain. Whereas Optimistic rollups assume that transaction data is accurate and reward the community for finding errors, ZK-Rollups ensure accuracy upfront while offering smoother performance and additional privacy.

The ADI Network is implemented as a zero-knowledge rollup (zkRollup) – a Layer 2 network that utilizes validity proofs to confirm every state transition. Transactions execute on the ADI Network off-chain environment, and the resulting state changes are periodically summarized. For each batch of L2 transactions, a ZK validity proof is generated, proving that the new L2 state is the result of correctly applying all those transactions. This proof, along with a small amount of data (such as the new state root or compressed transaction data), is submitted to an Ethereum smart contract on L1 called the Verifier. The Verifier contract verifies the proof and updates the official L1 record of the L2 state only if the proof is valid. This mechanism eliminates the need for a fraud challenge period; any invalid batch would be rejected immediately by L1, rather than relying on observers to catch fraud.

In contrast to the Optimistic Rollup design (which assumed correctness and gave a window for fraud proofs), the zkRollup provides provable correctness upfront. This yields instant L1 finality once a proof is accepted, and significantly shorter withdrawal times, since users need only wait for a proof to be generated and verified (typically seconds) instead of a week. Additionally, ZK proofs offer privacy benefits: the proof demonstrates validity without revealing all transaction details, allowing off-chain transaction data to remain minimally exposed.

Technical Note: Early ZK-Rollups were more complex to implement and initially limited in smart contract support. However, modern zkEVM technology (as used by ADI Network) has overcome these limitations, allowing full Ethereum compatibility with validity proofs. ADI Network uses a zkEVM approach where the L2 execution is Ethereum-equivalent, and proofs are generated for EVM state transitions. This ensures developers can deploy standard Solidity smart contracts on ADI Network with minimal changes, while benefiting from the security and speed of ZK-Rollup validation.