Quantum computing's rapid advancement poses a significant threat to the cryptocurrency world, with Bitcoin potentially facing a more severe challenge than Ethereum. Citi analysts warn that recent breakthroughs have accelerated the timeline for practical quantum attacks, and Bitcoin's exposure is primarily due to its governance structure. The issue lies in the exposure of public keys during transactions, which can be exploited by quantum attackers to derive private keys and redirect funds. Google's research suggests a 500,000-qubit machine could break Bitcoin's encryption in minutes, with Q-Day estimated for 2032. However, other researchers predict it could happen as early as 2030.
Bitcoin's conservative and consensus-driven model, while central to its credibility, also makes rapid protocol changes slow and contested. Transitioning to quantum-resistant cryptography would require broad consensus, extensive testing, and likely a hard fork, a challenging process. Ethereum and other proof-of-stake networks are better positioned due to their more flexible governance and history of regular protocol upgrades, but they are not immune to quantum attacks.
The scale of Bitcoin's dormant coin problem exacerbates the risk. An estimated 6.7 to 7 million BTC in wallets with exposed public keys are vulnerable, including 1 million Bitcoin mined by Satoshi Nakamoto, worth an estimated $82 billion. The analysts emphasize adaptability as the key to long-term resilience, highlighting proposed upgrades like BIP-360 and BIP-361. Citi's report aligns with the Fireblocks CEO's statement that Bitcoin's quantum challenge is a coordination issue, not a technical one, underscoring the need for swift and collective action to address this emerging threat.
