Quantum-proof Bitcoin signatures would clog network nodes with 10x larger data
Summary
Coinbase has highlighted the operational challenges of preparing Bitcoin wallets and custody systems for quantum-resistant signatures. The draft SHRINCS scheme offers compact stateful signatures but requires durable, non-reusable signing state and exclusive access during signing, complicating backups and multi-server exchange operations. If trustworthy state is missing, signers must use a larger stateless fallback signature. That increases transaction weight and potentially fees, though the article’s cost figures rely on a hypothetical model. SHRINCS remains a draft, with its security proof and optimized implementation unfinished; deployment designs and testing through recovery and server failures are still needed.
