Google’s Quantum AI team has warned that the cryptography securing Bitcoin and much of the digital asset market may be more vulnerable to future quantum computers than previously assumed. In a recent research blog post, the team said the quantum resources required to attack the elliptic curve cryptography widely used across blockchain networks could be lower than earlier projections.
Google raises concerns over elliptic curve security
The analysis focuses on elliptic curve cryptography (ECC), the foundation for digital signatures used to authenticate transactions on Bitcoin and many other blockchains. If sufficiently powerful, fault-tolerant quantum computers become available, algorithms such as Shor’s could, in principle, compromise ECC-based signatures.
Google’s researchers indicated that updated assessments of the quantum resources needed for such attacks suggest a potentially smaller gap between theoretical capability and practical feasibility than the industry has often assumed. While large-scale quantum computers do not exist today, the findings add urgency to planning for post-quantum defenses.
Why this matters for crypto networks
Bitcoin, Ethereum, and numerous other chains rely on ECC-based signature schemes (such as ECDSA and EdDSA) to verify ownership and authorize transfers. A successful quantum attack on these schemes could enable signature forgery, putting funds at risk once public keys are revealed on-chain during transaction spending.
By contrast, the hash functions used in address generation and proof-of-work are generally considered more resistant to quantum attacks, facing only quadratic speed-ups. The primary near-term concern centers on signature algorithms, not hashing.
Timelines remain uncertain, but preparation is underway
There is no evidence that a quantum computer capable of breaking ECC at scale exists today, and expert estimates on timelines vary widely. However, standards bodies and the broader security community are advancing post-quantum cryptography (PQC) to replace vulnerable schemes. The U.S. National Institute of Standards and Technology (NIST), for example, has selected candidate algorithms for standardization to help organizations transition to quantum-resistant signatures and key exchange.
For public blockchains, migration is complex. Networks will need to consider how to introduce PQC-compatible addresses and signatures, manage key rotation, preserve backward compatibility, and coordinate changes through consensus. Some projects and researchers are already exploring post-quantum signature options and upgrade paths, but broad adoption will take time.
Outlook
Google’s latest warning underscores the need for the crypto industry to accelerate post-quantum readiness. While immediate risk remains theoretical, the potential impact on digital asset security is significant, and the window for safe, orderly migration may be shorter than many previously expected.