Rust vs Move for Formal Verification of Smart Accounts

Established verification landscape: Mature tools like Prusti, Kani, and Creusot integrate with Cargo. This matters for teams already in the Rust ecosystem (e.g., Solana, NEAR, Polkadot) who need to verify custom account logic without learning a new stack.

Unconstrained programming model: Enables complex, non-standard account abstractions (e.g., multi-sig with time-locks, social recovery). This matters for protocols like EigenLayer AVSs or Cosmos zones that require bespoke security models beyond a standard asset ledger.

Linear types and bytecode verifier: The language enforces resource scarcity and absence of double-spends at the VM level. This matters for high-value DeFi accounts on Aptos or Sui, where guaranteed correctness for asset handling is non-negotiable.

Formal verification by default: Core libraries (like coin and token) are pre-verified. This matters for projects building on Aptos or Sui that can inherit safety from standard, audited account modules (e.g., Safe{Wallet}-like functionality), reducing custom code attack surface.

Leverage mature tooling: Integrate with the broader Rust ecosystem (Cargo, crates.io, 100k+ packages). This matters for teams already using Rust for off-chain services or other components, reducing context switching and enabling code reuse. Formal verification tools like Kani (AWS) and Prusti are built as compiler extensions, fitting into existing CI/CD workflows.

Fine-grained resource management: Rust provides direct control over memory and execution, enabling highly optimized smart accounts. This is critical for complex, stateful account logic where gas/minimal overhead is a primary constraint. You can verify low-level invariants that are closer to the final compiled bytecode.

Language-level safety guarantees: Move's bytecode verifier enforces critical invariants (no double spends, resource scarcity) by design, before formal tools are applied. This creates a higher baseline of security, reducing the verification burden. The type system (with copy, drop, store, key abilities) inherently prevents whole classes of vulnerabilities common in other VMs.

Native support for verified modules: Move prover specifications can be published and verified on-chain (e.g., Sui's sui move prove). This matters for protocols requiring transparent, auditable proof of correctness for deployed modules, enabling trustless verification by users and auditors directly from the blockchain state.

Cross-platform logic & maximum performance. Ideal when your smart account logic must be consistent across multiple execution environments (e.g., Solana Sealevel, CosmWasm, and your own indexer) or requires squeezing out every unit of gas/performance. Suits teams with deep Rust expertise prioritizing control.

Rapid, secure development on Aptos/Sui. The optimal choice when building natively on Move-based chains. The integrated toolchain (move prove) and inherent safety drastically reduce time-to-security for standard DeFi primitives (AMMs, lending vaults) and asset-centric smart accounts, minimizing bespoke verification effort.

Limited adoption & tooling: With ~5,000 total Move developers vs. Rust's 2M+, finding experienced auditors is harder. Ecosystem libraries (e.g., for signature schemes, oracles) are nascent compared to Rust's OpenZeppelin equivalents. This matters for protocols needing rapid iteration or those dependent on a broad set of pre-audited components.

Retrofitted safety: Formal verification is an add-on, not a language primitive. Engineers must manually annotate code with specifications, increasing development time by 30-50% for full coverage. This matters for startups with tight timelines or projects where the verification scope (e.g., entire state machine vs. critical functions) is unclear at the outset.