Quantum Threat to Ethereum: Google Lowers Hacking Threshold by 20 Times, but Protection Is Already on the Way
March 2026 marked the publication of a Google Quantum AI study that fundamentally changes the perception of Ethereum's security. According to new data, cracking the electronic signature scheme protecting every network account will require 20 times less computing power than previously assumed. This is no longer a hypothetical threat—timelines have been set, and so far, only one blockchain network is actively preparing to counter the attack.
Previously, it was believed that compromising ECDSA (the digital signature algorithm underlying Ethereum) would require tens of thousands of logical qubits. However, Google's work has reduced this estimate to approximately 1,200 qubits. The company considered this forecast realistic enough to set an internal deadline for migrating its own systems to 2029.
Why the New Estimate Is a Turning Point
The essence of the vulnerability is simple: when sending a transaction, an account reveals its public key. A sufficiently powerful quantum computer could compute the private key from it and drain the wallet. Modern quantum machines are not yet capable of this, but 1,200 qubits is a concrete benchmark that engineers can work toward. About 0.1% of funds on the Ethereum network reside at addresses with exposed public keys—such wallets are already vulnerable today.
It is important to understand that the quantum threat affects not only holders. At risk are validator signatures, data availability guarantees, and zero-knowledge proof systems that underpin most rollup protocols. All this infrastructure relies on mathematics that a sufficiently powerful quantum computer could break.
What the Ethereum Team Is Doing
In January 2026, the Ethereum Foundation formed a dedicated Post-Quantum Security team led by Tom Coratje. It operates fully transparently: all results are 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. These developments rely on three post-quantum cryptography standards approved by NIST in August 2024.
In the near term, EIP-8141 is being considered—a standard implementing account abstraction at the network level, allowing each account to choose its own signature scheme. It is planned to 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 milestone Google has set for its own systems. For those who want to protect themselves today, the Foundation's Kohaku project is suitable. It allows creating a quantum-resistant smart account based on the ERC-4337 standard, which relies on account abstraction. No hard fork is needed, and the cost of the procedure on the first-layer test network is approximately $0.07.
The Rest of the Blockchain Industry
No major blockchain has responded to the threat like Ethereum. Bitcoin, Solana, and others face similar vulnerabilities: the ECDSA signature scheme is used across the industry. However, 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 death sentence: significant engineering challenges remain before quantum hardware reaches this level. But a 20-fold reduction in the risk estimate, especially from one of the world's most advanced quantum programs, is not a signal the rest of the market can continue to postpone.
Analyst's opinion: The market as a whole underestimates the speed of quantum computing development. Ethereum demonstrates exemplary proactivity, but investors and developers of other networks should consider: if Google is already naming specific timelines, then preparation time is rapidly shrinking. There is no panic yet, but strategic planning should become the number one priority for the entire industry.