This time, it's not quantum FUD—Coinbase is already scheduling projects. On July 25, Brian Armstrong said on X that quantum computing is not an immediate threat to Bitcoin, but preparations need to be completed before sufficiently powerful machines emerge. Two days ago, Coinbase released its roadmap: within the next year, they plan to build a post-quantum signature pipeline, convene Bitcoin Core developers and cryptographers with Stanford in August to discuss migration, and allocate engineering resources to support BIP-360. Technically, the real danger lies in the signature layer. A sufficiently fault-tolerant quantum machine could use Shor's algorithm to derive private keys from exposed ECDSA or Schnorr public keys. P2PK, bare multisig, Taproot, and reused addresses would be the first to be affected. Coinbase estimates that there are about 1.7 million BTC in old P2PK addresses. As for SHA-256, Grover's algorithm mainly reduces the security margin, but it can't simply be described as "broken." The quantum threat isn't real today, but the migration work must start now. Bitcoin's slowest bottleneck might not be cryptography—it could be consensus coordination.