Google Quantum AI has published findings suggesting quantum computers may be able to break the elliptic curve cryptography that secures most blockchains, using far fewer resources than previously estimated. This development has raised serious concerns across the digital asset industry about the timeline for quantum-resistant upgrades.
Google team slashes resource estimates for quantum attacks
Researchers from Google Quantum AI, including Ethereum Foundation’s Justin Drake and Stanford’s Dan Boneh, outlined a new method that could compromise the elliptic curve cryptography known as ECDLP-256, which underpins the security of Bitcoin, Ethereum, and various other cryptocurrencies. Traditionally, this encryption scheme was considered safe, as classical computers would require billions of years to break it; however, quantum computers applying Shor’s algorithm can, in theory, achieve this in minutes.
The study presents two circuits capable of executing the attack: one uses under 1,200 logical qubits and 90 million operations, while the other needs fewer than 1,450 logical qubits and 70 million operations. Either approach is estimated to require fewer than 500,000 physical qubits—a dramatic reduction compared to earlier estimates that pegged this threshold at about 10 million qubits.
Despite these advances, Google has deliberately withheld the technical blueprints for these attack circuits. Instead, the team shared a zero-knowledge proof allowing others to verify the claim’s accuracy without exposing the detailed method. Google’s Ryan Babbush and Hartmut Neven stated that this decision aligns with established responsible disclosure practices within the cybersecurity community.
Google Quantum AI operates as the tech giant’s advanced research arm focused on quantum computing. The team has made several pioneering contributions to the field, working closely with researchers and academic partners to address both theoretical and applied issues in quantum algorithm design.
Crypto ecosystem faces timeline pressure for quantum transition
The findings warn that more than 1.7 million Bitcoin are stored in wallet formats with exposed public keys, increasing to 2.3 million BTC when additional script types are included. Other cryptocurrencies such as Ethereum and Solana face similar risks through various smart contract implementations, staking platforms, and data storage methods.
Google has set an internal 2029 deadline for its own migration to post-quantum cryptography, reflecting growing confidence that quantum threats may materialize sooner than previously expected. This has prompted several prominent voices in the digital asset sector to urge immediate preparation for quantum-safe upgrades.
Dragonfly Capital managing partner Haseeb Qureshi characterized the research as highly significant, advising that all blockchain networks should begin transition planning urgently. He described Google’s implementation of Shor’s algorithm as much more efficient than earlier projections and noted that post-quantum readiness could be needed by the decade’s end.
Castle Island Ventures co-founder Nic Carter called the whitepaper “very sobering,” noting that new quantum research is rapidly escalating the perceived urgency. He emphasized that quantum threats are now a tangible issue, rather than a distant hypothetical, and questioned whether the crypto sector can adapt before practical quantum attacks become possible.
Carter observed, “…and the craziest thing is that the Google Quantum AI paper (above) is maybe not even the most concerning quantum paper released today.”
