Coinbase warns that Proof-of-Stake blockchains like Ethereumn (ETH) and Solana (SOL) could face risks from quantum computers in the future, following the announcement of the first report from an independent quantum advisory board on April 22.
The report, conducted with researchers from Stanford, UT Austin, and the Ethereum Foundation, emphasizes that crypto remains safe from quantum for now, but preparation needs to start immediately before the threat becomes urgent — especially as the security structures of many blockchains could be affected if quantum computing capabilities reach a sufficiently strong threshold.
Coinbase Flags Quantum Risks for PoS
Coinbase is not issuing an “imminent threat” style warning, but framing the issue in a long-term context. In a recent post, Philip Martin, Coinbase CSO, emphasized that “crypto is safe today,” while noting that the industry needs to prepare before sufficiently powerful quantum systems emerge.
Today we’ve published the first position paper from the Coinbase Independent Advisory Board on Quantum Computing and Blockchain, a group of leading researchers from Stanford, UT Austin, the Ethereum Foundation, and beyond.
The short version: your crypto is safe today. But a…
— Philip Martin (@SecurityGuyPhil) April 21, 2026
This is the first report from the independent quantum advisory board established by Coinbase, with participation from researchers at academic institutions and the Ethereum Foundation. According to Coinbase, the group’s goal is to assess potential risks to current cryptographic systems and propose long-term preparation directions for the industry.
Research indicates that risk levels may vary between systems. Some blockchain protocols — especially Proof-of-Stake — may have a higher level of “exposure,” as the way public keys are used in the staking and validation process can increase exposure in certain attack scenarios.
Why PoS Faces Higher Exposure
Unlike Proof-of-Work, where public keys are usually only exposed when a transaction is performed, Proof-of-Stake protocols require validators to maintain their public keys in a public state for long periods to participate in the validation process.
This makes validators on PoS easier targets in a quantum computer attack scenario. If a sufficiently powerful quantum computer can derive a private key from a public key — an assumption related to the ability to break elliptic curve cryptography (ECDSA) — then the validator could become a direct target.
Ethereum total value staked. Source: CryptoQuant
Ethereum is currently the largest PoS network. About 32.3% of the total ETH supply is being staked, equivalent to about 39 million ETH, with a total staking market cap of around 94.4 billion USD. This means a significant portion of assets in the ecosystem depends on the security of validator keys.
On Solana, the risk level may be higher. About 68% of the total SOL supply is being staked, with a staking market cap of approximately 37.9 billion USD. As the stake ratio increases, the risk does not stop at individual accounts but could affect the entire PoS system if validators are compromised.
How Real Is the Threat Today
Both Coinbase and related studies emphasize that this risk is not yet immediate. Currently, there does not exist a cryptographically relevant quantum computer (CRQC) powerful enough to break encryption systems like ECDSA in real-world conditions.
A recent study from Google Quantum AI shows that under ideal conditions, a quantum system could derive a private key from a public key in just minutes — equivalent to the time it takes to create a Bitcoin block — opening an “on-spend attack” scenario where transactions could be replaced before they are confirmed.
However, this is still a theoretical model. Current quantum systems have not reached the necessary scale, and implementing a real-world attack still faces many technical hurdles. Therefore, the issue does not lie in the present, but in the fact that blockchain systems need to prepare before this threat computing becomes feasible. This is also why Coinbase emphasizes “prepare now, not when it’s urgent.”
Impact on Users
For regular users, the risk of being affected in the short term is very low, especially if using modern address standards where public keys are not exposed before a transaction.
Impact on Validators and Networks
For validators — especially on PoS networks — long-term exposure of public keys on the network makes them more vulnerable targets if a quantum attack becomes a reality.
At the systemic level, the potential risk is even greater. On Ethereum, controlling more than 1/3 of the stake can disrupt the finalization process; if it exceeds 2/3, an attacker can control the entire consensus mechanism. This turns a cryptography issue into a systemic risk.
How Ethereum and Solana Are Preparing
Major blockchains like Ethereum and Solana are still in the research and testing phase for response options to quantum computer risks, rather than deploying network-wide changes.
According to the Coinbase report, from user accounts to validators and zk (zero-knowledge) systems, many parts of Ethereum could be affected if quantum becomes feasible. Previously, Vitalik Buterin also mentioned a “quantum emergency” scenario, in which the network might need a hard fork to protect user funds. However, directions such as hash-based signatures or account abstraction still remain at the level of technical proposals.
For Solana, the network has introduced “Winternitz Vault,” allowing users to transfer assets to addresses using hash-based signatures. After the transfer, these assets are no longer vulnerable to quantum computer attacks.
A Long-Term Risk, Not Immediate
The warning from Coinbase is not a signal for an impending crisis, but a long-term risk to the security foundation of crypto.
For Proof-of-Stake networks like Ethereum and Solana, where validators directly participate in the validation process, transitioning to quantum-resistant systems may be more complex due to consensus mechanisms and the amount of assets being staked.
Instead of reacting after an incident occurs, organizations like Coinbase are trying to accelerate preparation in advance. As the gap between theory and reality narrows, the transition may need to take place before the threat truly emerges.
