# Challenges and Research Directions Integrating ZK wrappers with the EVM presents several technical challenges that must be addressed to ensure compatibility while preserving the security and privacy guarantees of the [[ZKP/Introduction/ZKP Ecosystem/Architecture|ZKP ecosystem:]] * **State Model Differences:** The [[ZKP/ZKP Base Layer/ZKP Blockchain/Technical Build Application Layer/Smart Contract Execution Environments EVM|EVM]] operates on an account-based model, whereas the ZKP ecosystem uses a commitment-based state model. Bidirectional state adapters are being developed to map EVM accounts to commitments, translate state transitions into zero-knowledge constraints, and maintain compatibility with Ethereum [19, 36, 47]. * **Gas Metering for ZKP Operations:** [[ZKP/ZKP Base Layer/ZKP Blockchain/Technical Build Application Layer/ZK Circuit Workflow in Privacy-Preserving Computations|ZKP operations]] have different costs than standard EVM operations. A dual gas accounting system, dynamic pricing, and economic models ensure fair pricing and incentives [19, 46]. * **Pre-compiled Contracts for ZK Operations:** [[ZKP/ZKP Base Layer/ZKP Blockchain/Technical Build Application Layer/Privacy-Preserving Computations with ZK Wrappers/Circuit Definition for Diverse AI Tasks/Circuit Definitions|ZK-friendly pre-compiles]] are planned to enhance efficiency, with formal verification ensuring equivalence to existing operations [30, 36]. The research focuses on maximizing bytecode compatibility with Ethereum while preserving security. ### Future Technical Specification A forthcoming specification will detail circuit optimization, gas models, APIs, and [[ZKP/Research/Privacy Pools for Scalability/Recursive Proofs for Batching|recursive SNARKs for scalability]] (π_{n+1} = Prove(π_n) [47, 49]). See also: [[ZKP/ZKP Base Layer/ZKP Blockchain/Storage Layer/Storage Layer|Storage Layer]]