Bitcoin Exchanges Face Quantum Computing Risk Ahead of Network Upgrade

Bitcoin exchanges and custodians are facing a challenge as they prepare for a potential quantum computer attack on the network. According to Coinbase, a workshop it hosted with Stanford and Localhost Research revealed no consensus on an exact post-quantum approach, but participants did identify open tradeoffs involving transaction size, hardware performance, key management, and adoption.

A recent Glassnode study found that roughly 1.6 million BTC in exchange-related outputs had public keys visible on-chain, which could be targeted by a future quantum computer without waiting for their owners to spend.

The study classified 4.12 million BTC, or 20.6% of the issued supply, as structurally exposed due to operational behavior such as address reuse or leaving a balance associated with a key after a spend revealed it. Exchange-related balances were the largest labeled part of that operational bucket, accounting for around 1.63 million BTC.

Coinbase called the risk non-immediate and emphasized that public-key visibility does not necessarily mean an immediate theft condition. However, exchanges can reduce their quantum exposure before a network upgrade by adopting new rules and using tools such as address hygiene, change-output rotation, and reserve management.