Time Runs Out for Bitcoin to Counter Quantum Threat as 6.9 Million BTC, Including Satoshi's, Are at Risk

Not all aspects of bitcoin are vulnerable to quantum computer attacks. The process of bitcoin mining, which utilizes a type of mathematics known as hashing, is secure against quantum computers. The blockchain itself and the rule that new bitcoins can only be created through mining would remain intact in the event of a quantum attack, with blocks continuing to be produced and the chain remaining operational. However, ownership would be severely compromised. Bitcoin wallets rely on a different mathematical approach that converts a private key into a public address, and this is the primary obstacle preventing unauthorized access to funds. A quantum algorithm, known as Shor's algorithm, can bypass this security measure, and recent research has shown that such an attack could be executed with fewer resources than previously thought, within a timeframe that competes with bitcoin's block times. This article explores the potential risks, the current state of bitcoin's defenses, and whether the network can coordinate a significant security upgrade before quantum computing technology advances. Approximately 6.9 million bitcoins, roughly one-third of all mined bitcoins, are stored in wallets with publicly visible keys, making them susceptible to quantum attacks. This includes early bitcoins and any wallet that has been used for transactions, as spending reveals the key. The 2021 Taproot upgrade inadvertently expanded the problem by publishing keys for any spent bitcoins. While there are proposals to address this issue, such as introducing quantum-safe address types or a detection system for quantum attacks, none have gained broad support from bitcoin's core developers. The lack of a centralized authority and a governance process makes it challenging for bitcoin to implement effective solutions. Ethereum, on the other hand, has a formal quantum-resistant program in place, with multiple teams working on the migration to quantum-safe mathematics. The question remains whether bitcoin can coordinate a significant security upgrade before the threat becomes reality.