Coinbase advisory council flags quantum risk to 7 million Bitcoin

A Quantum Advisory Council convened by Coinbase, including leading cryptographers, issued a report urging the Bitcoin community to start planning post‑quantum cryptographic upgrades.

The report estimates roughly 7 million BTC—about 35 % of circulating supply—are vulnerable because their public keys are exposed in legacy pay‑to‑public‑key (P2PK) addresses or through address reuse, including around 1.7 million BTC tied to early‑mined coins.

While current quantum computers cannot break today’s signatures, the council warns that future attacks could threaten those funds and trigger market disruption. It outlines governance options: enforce a hard migration deadline that could freeze or burn unmigrated coins, preserve ownership rights and take no action, or adopt intermediate measures such as rate‑limiting withdrawals or zero‑knowledge proofs (e.g., BIP‑361).

The council recommends separating technical development of quantum‑safe signatures from the governance debate so the network can test upgrades before any quantum threat materialises.