Ethereum co-founder Vitalik Buterin proposed a roadmap to address four parts of the network he sees as most vulnerable to quantum attacks: validator signatures, data storage, user account signatures, and zero-knowledge proofs.
With rising concern about quantum-capable computers threatening blockchains, Buterin posted the plan noting each area’s proposed fix and engineering challenges. For consensus validator signatures, he recommends replacing BLS (Boneh-Lynn-Shacham) with “Lean” quantum-safe hash-based signatures. The key difficulty is choosing a hash function carefully, since it would likely be a long-term choice—“this may be ‘Ethereum’s last hash function,’” he warned.
On data storage (“blobs”), Ethereum currently uses KZG (Kate-Zaverucha-Goldberg) commitments. Buterin’s roadmap favors switching to STARKs (Zero-Knowledge Scalable Transparent Argument of Knowledge), which are quantum-resistant, though the migration requires substantial engineering work.
User accounts today rely on ECDSA (Elliptic Curve Digital Signature Algorithm). The roadmap calls for enabling accounts to accept arbitrary signature schemes, including quantum-resistant lattice-based schemes. Those signatures are presently much heavier computationally and would increase gas costs. Buterin points to a long-term solution: protocol-layer recursive signature and proof aggregation to bring those overheads close to zero.
Quantum-resistant zero-knowledge proofs are currently very expensive to verify onchain. Again, Buterin emphasizes protocol-level recursion and aggregation: instead of individually verifying thousands of signatures and proofs, a single master proof or “validation frame” would validate many at once, keeping onchain costs minimal. He described blocks potentially containing many validation frames, each holding compact aggregated signatures or larger proofs.
Buterin referenced earlier proposals, including Justin Drake’s “Lean Ethereum” plan to harden the protocol. He also commented on the Ethereum Foundation’s “Strawmap,” expecting continued reductions in slot time and finality time as development progresses.
The roadmap outlines feasible technical paths but underscores significant engineering and design choices—especially around hash-function selection, tooling for STARKs, and building recursive aggregation—to make Ethereum resilient against future quantum threats.
