Google Dramatically Lowers the Quantum Threat to Ethereum, and the Network Is Getting Ready

Google has sharply lowered the computing power needed for an attack on Ethereum. That is pushing the network to move faster on post-quantum security.

Key Takeaways

• In March 2026, Google lowered the estimated quantum requirement to crack Ethereum accounts to about 1,200 qubits.
• Ethereum set up a Post-Quantum Security team in January 2026 and is working on solutions like EIP-8141 and Kohaku.
• Other blockchains like Bitcoin and Solana share similar ECDSA weaknesses, but they do not yet have a comparable post-quantum roadmap.

In March 2026, Google published a groundbreaking Quantum AI research paper that cuts the number of qubits needed to crack the security of Ethereum accounts by a factor of 20. Where people once thought tens of thousands of logical qubits would be needed, the research says about 1,200 qubits should be enough. That shifts the quantum threat from a theoretical issue to something that needs planning and preparation.

Quantum Risk and Ethereum's Weak Spots

Ethereum uses the Elliptic Curve Digital Signature Algorithm (ECDSA) to verify transactions. Every transaction reveals an account's public key, which could let a powerful enough quantum computer figure out the private key. That could drain wallets. While today's quantum hardware still cannot do this, the 1,200-qubit figure is a realistic benchmark for engineers to plan around. A small share of Ethereum funds, about 0.1%, is already in accounts that have exposed their public key and are therefore vulnerable right now.

Other parts of the Ethereum ecosystem are also exposed to quantum attacks, including validator signatures, data availability commitments, and the zero-knowledge proof systems that power many rollups. These rely on mathematical principles that powerful quantum computers could break.

Ethereum's Strategy for Post-Quantum Security

The Ethereum Foundation launched a dedicated Post-Quantum Security team in January 2026, led by Thomas Coratger. The team is working openly on solutions and keeping the community updated through pq.ethereum.org. Researchers like Justin Drake see post-quantum security as a top priority.

One major push is the Poseidon Prize, a $1 million award that supports research into improved hash-based cryptographic primitives. This lines up with the post-quantum cryptography standards finalized by the National Institute of Standards and Technology (NIST) in August 2024.

In the near term, EIP-8141 is being considered, a proposal that introduces native account abstraction and lets users choose their own signature algorithm. It could be rolled out during the Hegotá hard fork in the second half of 2026. The full move to a quantum-safe protocol version is aimed at around 2029, in line with the deadline Google has set for its own systems.

For users who want to get ahead of this now, the Kohaku project offers a way to create quantum-resistant smart accounts through the ERC-4337 standard, without needing a hard fork. That can already be done on the Layer 1 testnet for just a fraction of a dollar.

Quantum Threat and the Broader Crypto Market

Other major blockchains like Bitcoin and Solana share similar weaknesses because they also use ECDSA. But none of these networks has published a comparable institutional approach or post-quantum security roadmap so far. Google's sharp reduction in the required number of qubits, from one of the most advanced quantum programs, makes it clear that the quantum threat is no longer just a future concern.

Even though there are still technical hurdles before hardware reaches those capabilities, the crypto market can no longer ignore this development. Ethereum is leading the way with concrete steps and investments to protect against quantum attacks.

Why This Matters for European Crypto Users

The European crypto market, with its growing adoption and regulation, could benefit from progress on post-quantum security. Ethereum's active approach and the integration of new cryptographic standards could serve as a model for European projects and regulation. That could strengthen security and trust in blockchain technology across Europe as the quantum threat becomes more real.