Google Warns Quantum Risks Could Expose $100 Billion in Ethereum Assets

Much of the online reaction to Google’s recent research on quantum computing and blockchain security has focused on Bitcoin, particularly the speed at which a quantum attack could occur and the risk of stolen assets. However, researchers say Ethereum may face broader and more complex risks that have received less attention.

A new research paper examining quantum computing threats outlines several potential attack vectors that could impact Ethereum’s network, smart contracts, and digital assets. Estimates suggest that more than $100 billion in assets could be exposed to risk if quantum computing capabilities reach a sufficiently advanced level.

Public Key Exposure Creates Additional Risk

One of the key differences between Ethereum and Bitcoin lies in how public keys are handled. In Bitcoin, public keys are typically hidden behind cryptographic hashes until a transaction is executed. In Ethereum, however, a public key becomes visible once a transaction is made and remains visible permanently.

Because Ethereum accounts are tied directly to public keys that cannot be changed without moving funds to a new account, wallets holding large amounts of assets could become targets for quantum attacks. Researchers estimate that large wallets containing significant amounts of ether could potentially be compromised within days if advanced quantum computers become capable of breaking current cryptographic systems.

Smart Contracts and Stablecoins Could Be Vulnerable

Smart contracts introduce additional risk because administrative accounts often have powerful permissions, such as pausing contracts, upgrading code, or moving funds. If the private keys controlling these administrative functions were compromised, attackers could gain control over major decentralized applications.

This risk extends to stablecoins issued on Ethereum. Administrative keys often control token minting and contract management functions. If those keys were compromised, it could theoretically allow attackers to mint unlimited tokens or disrupt major digital asset markets.

Layer-2 Networks Add Another Layer of Risk

Ethereum relies heavily on Layer-2 networks to process transactions and scale the ecosystem. These networks store large amounts of digital assets and rely on cryptographic systems that may also be vulnerable to future quantum attacks.

Because significant amounts of ether and tokens are locked in Layer-2 systems, vulnerabilities at this level could expose additional assets to risk. Some networks that rely on different cryptographic techniques may be more resistant to quantum threats, but the broader Layer-2 ecosystem could still face challenges.

Proof-of-Stake Security Could Also Be Affected

Ethereum’s proof-of-stake system relies on validators who use digital signatures to confirm transactions and secure the network. If quantum computers were able to break these cryptographic signatures, attackers could potentially impersonate validators or gain control over a portion of the network.

In extreme scenarios, this could allow attackers to disrupt the network, censor transactions, or potentially rewrite parts of the blockchain ledger.

Upgrading the Network Will Be Complex

Researchers note that transitioning to quantum-resistant cryptography will not be simple. Updating the core Ethereum protocol would only be part of the solution. Smart contracts, decentralized applications, Layer-2 networks, and infrastructure providers would all need to upgrade their cryptographic systems independently.

Because Ethereum operates as a decentralized ecosystem without a central authority controlling all applications and protocols, coordinating such a transition could be complex and time-consuming.

A Long-Term but Important Risk

While quantum computing threats are still largely theoretical and may take years to materialize, researchers warn that the risks should be taken seriously. The potential impact would not be limited to a single vulnerability but could affect multiple layers of the Ethereum ecosystem, including wallets, smart contracts, stablecoins, and network security.

As quantum computing technology continues to advance, blockchain networks may need to begin transitioning toward quantum-resistant cryptography to ensure the long-term security of decentralized financial systems and digital assets.