Overview
- In an October 13 technical paper Coinbase urged Bitcoin developers to start multi-year preparations to add quantum-resistant signature options and said the move could take several years to complete.
- The paper backs flexible transaction templates such as BIP-360 and P2TRv2 and recommends hybrid 1-of-2 wallets that let existing ECDSA or Schnorr keys coexist with a separate post-quantum key for phased migration.
- Coinbase told custodians to prefer signature schemes that work with multiparty computation and warned that stateful post-quantum algorithms can be dangerous if signing state is lost or duplicated because reuse can allow signature forgeries.
- The company did not say a quantum computer has already broken Bitcoin and said it has begun adapting its own custody systems while contributing to open research and the Bitcoin Security Consortium.
- Moving to post-quantum signatures will force tradeoffs — larger signatures can raise fees, nodes may need more verification resources, hardware wallets will need updates and any change will require wide testing and community consensus before activation.