Tldr:
- Quantum computing could break Bitcoin’s encryption, with Q-Day set to fall between 2030 and 2032, Citi warns.
- An estimated 6.7 to 7 million Bitcoins in exposed wallets make Bitcoin a prime target for a quantum attack.
- Ethereum’s flexible governance enables it to adapt more easily against the threat of quantum computing.
- Fireblocks CEO describes Bitcoin’s quantum risks as a coordination problem and points to the existence of post-quantum tools.
Quantum computing poses a growing threat to the cryptocurrency sector. According to new Citi Research Note. The report warns that Bitcoin faces much greater exposure than Ethereum.
Analysts believe that this division is due to governance and not technology alone. Recent breakthroughs have pushed the estimated timeline for practical quantum attacks to as early as the 2030s.
With millions of bitcoins already at risk, the industry is watching closely. Analysts say the window of preparation is rapidly narrowing.
Bitcoin’s structural vulnerability to quantum attacks
Bitcoin transactions expose the sender’s public key to the network until they are confirmed. This creates a window where a quantum attacker could theoretically extract a private key.
From there, the attacker can redirect the funds before the transaction is completed. The exposure is short but real, and is getting more serious as quantum computing hardware improves.
Google research It is suggested that a 500,000-bit machine could break Bitcoin’s encryption in minutes. No such machine currently exists, but the pace of progress is accelerating.
Google puts its Q-Day estimate at 2032, while some researchers suggest 2030. Either way, the cryptocurrency industry has limited time to act.
The idle wallet problem makes Bitcoin exposure even more urgent. There is an estimated 6.7 to 7 million Bitcoins in wallets with public keys already exposed. These wallets represent a focused and attractive target for any future quantum-capable actor.
Of those wallets, nearly 1 million Bitcoins are believed to have been mined Satoshi Nakamoto remain untouched. These currencies use early address formats that are particularly vulnerable to quantum attacks. Its value at current prices amounts to about $82 billion.
A governance gap separates Bitcoin and Ethereum
Ethereum and others Proof of stake Citi analysts said the networks were better placed to adapt. Its more flexible management allows for faster changes to the protocol when needed.
Ethereum also has a proven history of regular protocol upgrades. This flexibility gives it a structural advantage against the threat of quantum computing.
Bitcoin’s conservative, consensus-based model is widely viewed as fundamental to its credibility. However, this same model makes quick changes to the protocol slow and contentious.
Moving to quantum-resistant encryption will likely require a hard fork, which is a notoriously difficult process. Broad network consensus must be achieved before any changes can take effect.
Michael Shawlov, CEO of Fireblocks, addressed this at the Financial Times’ Digital Assets Summit, arguing that the threat “is not actually as much of a threat as people make it out to be.”
He described Bitcoin’s quantum challenge as “mostly a coordination issue” for the community rather than a technical problem.
Shaulov also noted that “the entire Internet industry needs to jump in and start using it fundamentally Post-quantum encryption,” adding that “generally speaking, we have the algorithm available.” His statements suggest that preparedness, not the threat itself, remains the real challenge.
Citi analysts have pointed to BIP-360 and BIP-361 as proposed Bitcoin upgrades worth monitoring. Meanwhile, Ethereum is not completely immune to quantum threats either.
A quantum attacker could theoretically obtain enough private keys to control 33% of staked assets. This may allow disruption of the final block or wider network operations.
