- Future quantum computers could break elliptic curve cryptography (ECC) used in cryptocurrencies
- New research shows significantly fewer qubits and gates are required than previously estimated
- Google urges transition to post-quantum cryptography (PQC)
- Vulnerabilities disclosed responsibly using zero-knowledge proofs
- A transition timeline toward quantum-resistant systems is projected around 2029
Quantum Risks to Cryptocurrency Security
Google has released a new research paper outlining how future quantum computers could potentially compromise widely used cryptographic systems, including those securing cryptocurrencies. The study focuses on elliptic curve cryptography (ECC), particularly the 256-bit elliptic curve discrete logarithm problem (ECDLP-256), a core component of blockchain security.
According to the findings, quantum systems may require significantly fewer resources to break ECC than earlier estimates suggested. Google designed two quantum circuits based on Shor’s algorithm:
- One requiring fewer than 1,200 logical qubits and 90 million Toffoli gates
- Another requiring fewer than 1,450 logical qubits and 70 million Toffoli gates
These circuits could potentially operate on a cryptographically relevant quantum computer (CRQC) with fewer than 500,000 physical qubits, completing the task in minutes. This represents roughly a 20× reduction in required resources compared to prior estimates.
Push Toward Post-Quantum Cryptography
Most blockchain networks today rely on ECC, making them vulnerable to future quantum advancements. Google emphasizes that post-quantum cryptography (PQC) provides a viable long-term solution. These systems are specifically designed to withstand quantum-based attacks and ensure continued network security.
The company notes that transitioning to PQC will take time, increasing the urgency for early adoption. Suggested precautions include:
- Avoiding reuse of wallet addresses
- Minimizing exposure of public keys
- Considering policies for dormant or lost crypto assets
Google also highlighted ongoing collaboration across the industry, including efforts involving Coinbase, the Stanford Institute for Blockchain Research, and the Ethereum Foundation.
Responsible Disclosure Strategy
To reduce risks associated with exposing sensitive vulnerabilities, Google adopted a responsible disclosure approach. Instead of releasing detailed exploit methods, the company used zero-knowledge proofs to validate its research while preventing misuse. Google also coordinated with U.S. government bodies and encouraged similar practices across the research community.
Looking Ahead: The report highlights the complexity of vulnerability disclosure in crypto markets, where public perception can directly impact asset value. Rather than signaling immediate danger, Google positions its findings as a forward-looking assessment aimed at strengthening long-term resilience across blockchain ecosystems. With a projected transition timeline around 2029, the industry is being urged to begin preparing now for a post-quantum future.
