Quantum-proof Bitcoin signatures would clog network nodes with 10x larger data

Coinbase’s push to prepare Bitcoin for quantum computing addresses what happens when a wallet returns from an old backup or a signing server fails. Brian Armstrong called on Oct. 20 for preparation and collaboration across the industry. The operational detail comes from Shashank Agrawal’s Oct. 13 Coinbase article, which asks prospective signature schemes to work with ordinary wallets, recovery procedures, and independently operating custody servers. SHRINCS, a draft hash-based signature scheme for Bitcoin, combines smaller signatures that require a reliable record of previous signing with a larger fallback that works without that record. Under its current rules, recovery with uncertain state means taking the larger path. That preserves a route to signing for someone who can recover the secret.

First reported by CryptoSlate. This page is a short excerpt; the full text is theirs.