Bitcoin Quantum Resistance Roadmap Takes Shape Amid Growing Concerns
The Bitcoin community is working on a roadmap to ensure the cryptocurrency's quantum-resistance. Researchers are examining two proposals, BIP-360 and SHRINCS, which aim to protect funds from being compromised by future quantum computers.
BIP-360 proposes using P2MR output to commit funds to a Merkle root, reducing long-term public-key exposure. However, it would not protect against attacks during the period when spending reveals a vulnerable key. Its role is to create an upgrade path for future quantum-resistant signatures.
SHRINCS, on the other hand, relies on SHA-256 and combines two signing paths under one public key. It provides compact, stateful signatures that start at 324 bytes, requiring wallets to track signing history. If this history disappears after a backup restoration, a larger, stateless signature provides a recovery path.
The proposals concern advanced preparation for the potential threat of quantum computers. Even with suitable cryptography, users would need time and compatible tools to move coins before a cryptographically relevant quantum computer threatens existing keys. Exchanges, custodians, and wallet providers would need to coordinate this transition, which could increase demand for limited block space, raise transaction fees, and complicate transfers from institutional custody arrangements.