Ethereum's transaction validity model is currently anchored in ECDSA over secp256k1, whose security assumptions weaken in the presence of large-scale quantum adversaries. While NIST-standardized post-quantum signature schemes such as ML-DSA, SLH-DSA, and FALCON provide resistance against quantum attacks, integrating these schemes into Ethereum introduces significant systems-level challenges involving bounded execution, gas determinism, and adversarial verification complexity.

This paper introduces PQSigAbstract, a modular post-quantum signature verification architecture for Ethereum that separates validation into a stateless pre-validation phase and a deferred cryptographic verification phase linked through commitment binding. The design defines typed Verification Modules with explicit gas estimation, a versioned Scheme Registry with quarantine-based deployment safety, and a probabilistic aggregation mechanism for non-aggregatable post-quantum schemes.

The proposed architecture preserves EU-CMA security while maintaining compatibility with ERC-4337 and RIP-7560 account abstraction models. Formal gas cost models are derived for ML-DSA-44, FALCON-512, and SLH-DSA-128f, and empirical evaluation demonstrates practical deployment feasibility for high-value Ethereum accounts despite substantially higher verification costs relative to ECDSA.