Ethereum's journey towards quantum resistance is multifaceted, involving significant upgrades to its cryptographic foundations.
At the heart of this effort lies Vitalik Buterin's four-pronged approach, addressing four critical domains: validator signatures, data storage, user account signatures, and zero-knowledge proofs. By tackling these areas simultaneously, Ethereum aims to fortify its defenses against potential quantum threats.
The plan calls for replacing current Boneh-Lynn-Shacham (BLS) consensus signatures with a lean, hash-based alternative. This move is crucial in preserving the integrity of validator operations while mitigating the risk that quantum computers could break existing signatures used to attest to blocks and transactions.
Moreover, the data layer would transition away from KZG-based storage to STARKs, ensuring data proofs remain verifiable even under quantum pressure. This shift requires substantial engineering effort but would address a core vulnerability without compromising network performance.
Additionally, the plan envisions broader compatibility with signature schemes beyond ECDSA, including lattice-based approaches resistant to quantum attacks. However, this comes with the practical challenge of gas consumption: quantum-safe signatures tend to be heavier to compute, which could elevate gas costs in the near term.