Time's Running Out for Bitcoin to Counter Quantum Threat

While not all aspects of bitcoin are vulnerable to quantum computers, the ownership of coins is at risk. Bitcoin mining, which utilizes a type of math known as hashing, is not susceptible to quantum attacks. However, the math that protects bitcoin wallets, turning a private key into a public address, can be compromised by a quantum computer. A quantum algorithm known as Shor's can reverse this process, potentially allowing an attacker to access the private key. Google recently published a paper demonstrating that this attack can be executed with fewer resources than previously thought, highlighting the urgency of the situation. Approximately 6.9 million bitcoin, including those owned by Satoshi Nakamoto, are at risk due to exposed public keys. The 2021 Taproot upgrade has further expanded the problem. While Ethereum has a formal quantum-resistant program in place, Bitcoin developers have yet to propose a concrete solution. Several proposals, including BIP-360 and a detection system from BitMEX Research, have been put forth, but none have gained broad support from core developers. The lack of a centralized authority and governance process in Bitcoin makes it challenging to implement effective solutions, unlike Ethereum, which has a foundation and a governance process in place. The coordination problem lies in making decisions that the network has historically avoided, such as freezing old address formats or allowing exposed coins to move to new quantum-safe addresses. The window to respond to the quantum threat may be shorter than estimated, and developers must decide whether to start working on a solution now or wait until the threat becomes more apparent.