Banks Face 2027 Deadline to Adapt to Ethereum's Post-Quantum Migration

Ethereum's post-quantum migration has a potentially disastrous consequence for regulated banks: it may put them on a 2027 deadline to adapt. Thomas Brunner, Sygnum Bank's Head of Custody and Staking, believes that the current setup could cause significant problems for banks years before any quantum computer poses a real threat.

The Ethereum team has outlined a roadmap for its post-quantum migration, with layer-1 upgrades expected to be completed by 2029. However, Brunner warns that banks face a multi-year timeline to adapt due to the complexity of the process and their reliance on hardware security modules (HSMs).

Brunner emphasizes that a full cryptographic inventory, which maps every key and dependency, typically takes six months to a year to complete. Banks also need to redesign key ceremonies and dual-control procedures, followed by internal risk approval, external audit, and supervisory review.