Quantum Threat to Ethereum: Google Reduces Hacking Threshold by 20 Times, but Protection Is Already on the Way
Google Quantum AI's March 2026 publication served as a wake-up call for the entire crypto industry. According to their work, breaking the digital signature algorithm protecting Ethereum accounts will require 20 times fewer computational resources than previously estimated. This involves reducing the estimate from tens of thousands of logical qubits to approximately 1,200. The company considers this forecast realistic enough to set an internal deadline for migrating its own systems to post-quantum cryptography by 2029.
Why the new estimate changes everything
Ethereum's security is based on ECDSA (Elliptic Curve Digital Signature Algorithm). Each transaction reveals the sender's public key. A powerful quantum computer could derive the private key from it and drain the wallet. Current machines cannot do this, but 1,200 qubits is already a concrete benchmark that engineers can work towards. Particularly concerning is that about 0.1% of funds on the Ethereum network are on addresses with exposed public keys — such wallets are already vulnerable today. This threat affects not only holders but also validators and the zero-knowledge proof systems (ZK-proofs) that underpin most rollup protocols.
The Ethereum team is taking action
In January 2026, the Ethereum Foundation assembled a dedicated Post-Quantum Security team led by Tom Coratger. All results are publicly available on the project's website. One of the key researchers, Justin Drake, considers protection against the quantum threat a top strategic priority. The Foundation announced the Poseidon Prize — a $1 million award for breakthrough solutions in hash-based cryptography, based on three NIST standards approved in 2024.
In the near term, EIP-8141 is being considered — a standard that implements account abstraction at the network level and allows each user to choose their own signature scheme. It will be included in the Hegota hard fork, scheduled for the second half of 2026. Ethereum aims to complete its technical overhaul by approximately 2029 — the same deadline as Google. For those who want to protect themselves today, the Foundation's Kohaku project offers a way to create a quantum-resistant smart account based on ERC-4337 without a hard fork, costing about $0.07 on the test network.
The rest of the blockchain industry
No major blockchain has responded to the threat like Ethereum. Bitcoin, Solana, and others face the same vulnerabilities: the ECDSA signature scheme is used across the industry. But no project has assembled a dedicated post-quantum security team or presented a comparable action plan. The figure of 1,200 qubits is not yet a verdict: significant engineering challenges remain before quantum hardware reaches this level. However, a 20-fold reduction in risk assessment from one of the world's most advanced quantum programs is not a signal the market can ignore.
My analysis: Ethereum demonstrates maturity by building the infrastructure for the transition. But for other projects, delay is becoming increasingly risky. 2029 is not a distant future, but a horizon that will require immediate action from every market participant.