Sygnum executive says banks should prepare by 2027 for Ethereum quantum shift

Sygnum’s head of custody and staking, Thomas Brunner, said banks should begin preparing in 2027 if they want enough time to overhaul custody systems ahead of Ethereum’s planned quantum-resistant transition in 2029, according to CryptoSlate. Brunner explained future quantum-resistant signature methods would require strict controls, including a ban on reusing the same key, while banks often duplicate systems or roll them back to earlier states during backup and disaster recovery processes, creating conflicts with existing operating models. Brunner added that identifying a bank’s cryptographic keys and related systems alone can take six months to one year, followed by hardware support, certification, internal reviews, external audits and regulatory reviews. Meanwhile, Ethereum developers are considering completing a quantum-resistant transition for Layer 1 by 2029, although the timeline has not been finalized.