TL;DR:
- Adam Back proposed optional quantum-resistance upgrades for Bitcoin, in contrast to BIP-361, which calls for a forced freeze of vulnerable coins.
- Google Quantum AI published research showing that quantum computers could break Bitcoin’s cryptography with 20 times fewer physical qubits.
- Around 6.9 million BTC are vulnerable to quantum attack, including coins attributed to Satoshi Nakamoto.
Adam Back, CEO of Blockstream, presented at Paris Blockchain Week a proposal for optional quantum-resistance upgrades for Bitcoin, in direct opposition to BIP-361, an initiative that contemplates mandatorily freezing coins considered vulnerable to this technological threat.
“Preparation is key. Making changes in a controlled manner is much safer than reacting to a crisis,” Back declared during the event. Back also highlighted the emergency coordination capacity that the Bitcoin network has demonstrated throughout its history: “Bugs have been identified and fixed within hours. When something becomes urgent, attention grows and consensus follows.”
The Quantum Threat Divides Bitcoin Developers
Back’s stance contrasts with BIP-361, a proposal drafted by Jameson Lopp and five other developers, updated on April 15 in the official Bitcoin repository under the title “Post Quantum Migration and Legacy Signature Sunset“. This scheme proposes a staged soft hard fork that, in its final phase, would freeze coins that fail to migrate to addresses resistant to quantum computing, including funds attributed to Bitcoin’s anonymous creator, Satoshi Nakamoto.
The debate erupted following the publication of new research by Google Quantum AI last month. According to that work, a superconducting qubit system would need fewer than 500,000 physical qubits to break Bitcoin’s elliptic curve cryptography in a matter of minutes, a reduction of 20 times compared to previous estimates. Researchers calculate that approximately 6.9 million BTC are exposed to this vulnerability, of which around 1.7 million correspond to mining rewards from the Satoshi era.
Canary Funds and Other Alternatives
BitMEX Research published yesterday an alternative approach proposing the creation of a “Canary Fund” composed of coins vulnerable to quantum attack. The idea is that a full freeze would only be triggered if a spend is detected from that address, functioning as an early warning signal. Other researchers are exploring the possibility of implementing quantum-resistant transactions without the need for a network fork. Outside the Bitcoin ecosystem, networks such as Ethereum, Solana, and Naoris Protocol are also working on quantum-resistance solutions, making “Q-Day” a cross-cutting concern for the entire crypto industry.
