Research highlights Bitcoin’s cryptographic vulnerability to quantum computing advances, posing greater risks than Ethereum by 2026.
Citi analysts have identified a heightened quantum computing risk for Bitcoin compared to Ethereum, citing a research note published on May 18. The findings suggest Bitcoin’s foundational cryptography is significantly more vulnerable to attacks from advanced quantum computers, with required resources now estimated at 20 times lower than previously thought.
A landmark study by Google Quantum AI, Stanford University, and the Ethereum Foundation in late March corroborated these concerns. The report indicated a quantum computer with fewer than 500,000 physical qubits could break Bitcoin’s security, a threshold far lower than earlier projections. Ethereum’s governance and technological structure mitigate similar risks more effectively.
The analysis underscores a growing divergence in institutional confidence, with some firms reallocating holdings from Bitcoin to Ethereum. The timeline for potential quantum threats has accelerated, with March 30, 2026, marked as a critical inflection point for digital asset security.