Google: In the future, elliptic curve cryptography can be cracked with fewer resources. It is recommended that blockchains migrate to post-quantum cryptography before 2029.

Deep Tide TechFlow message: On March 31, Google’s Quantum AI team released a white paper stating that the number of qubits and gate operations required for future cryptography-related quantum computers (CRQC) is lower than previously expected—enough to break the elliptic-curve cryptography (ECC) currently widely used for encrypting cryptocurrencies.

The white paper shows that the research team compiled two quantum circuits targeting the 256-bit elliptic-curve discrete logarithm problem (ECDLP-256): one uses fewer than 1,200 logical qubits and 90 million Toffoli gates, and the other uses fewer than 1,450 logical qubits and 70 million Toffoli gates. Estimates suggest that the above circuits could complete the computation in minutes on a superconducting quantum computer with fewer than 500,000 physical qubits, reducing the required physical qubits by about 20x compared with what was previously needed.

Google previously published a migration timeline for 2029, urging the cryptocurrency community to migrate blockchains to post-quantum cryptography (PQC) before that deadline, and calling for avoiding the exposure or repeated use of wallet addresses with known vulnerabilities. For how vulnerability disclosures are handled, Google uses zero-knowledge proofs to publish resource estimates, enabling third-party verification without revealing attack details. Google says it will continue collaborating with organizations such as Coinbase, the Stanford Blockchain Research Institute, and the Ethereum Foundation to advance related work.