Coinbase Warns Quantum Computing Could Threaten Crypto Security

Coinbase’s Quantum Advisory Board has released a detailed report warning that quantum computing could pose a future threat to cryptocurrency security, though no immediate risk exists. According to Coinbase CSO Philip Martin, the report was published on April 21, 2026, and includes researchers from Stanford, UT Austin, UC Santa Barbara, Bar-Ilan University, and major crypto projects. The board emphasizes that the industry should begin preparing now to address potential vulnerabilities, as waiting could make mitigation significantly more difficult.

Quantum Risk Assessment

Experts agree that quantum computing does not currently pose an immediate threat to blockchain security. Today’s machines lack the power to break existing blockchain systems, though this could change within the next decade. The primary concern is not blockchain infrastructure itself, but rather wallet-level cryptography and user security.

According to the report, approximately 6.9 million BTC could be exposed because their cryptographic keys are already public. If quantum computers become sufficiently powerful, they could potentially break these signatures and access funds. Proof-of-stake networks face additional risk due to how validators operate, making user security the larger issue rather than the blockchain infrastructure.

Implementation Challenges

Quantum-resistant cryptography solutions have already been developed, and new standards have been approved. However, the real challenge lies in implementation. Upgrading millions of wallets, networks, and systems will require years of coordination and effort. These new cryptographic systems are also computationally heavier, which could affect transaction speed and costs.

Coinbase stated it is working with partners and developers to ensure systems are ready for transition when necessary, stressing that no single company can solve this challenge alone.

Hoskinson’s Criticism of Bitcoin’s Approach

Cardano founder Charles Hoskinson has raised concerns about Bitcoin’s strategy for addressing quantum risk. On April 21, 2026, Hoskinson criticized Adam Back’s approach of using SPHINCS+, a quantum-safe signature system, calling it “safe but too limited and inefficient.” In a social media post, Hoskinson stated: “Lol, let’s use the least expressive and interesting PQS to solve the quantum issue. Never change Bitcoin.”

According to Hoskinson, while SPHINCS+ solves the immediate problem, it does not improve Bitcoin’s overall capabilities. He believes a more advanced and adaptable solution should have been considered. He also warned that once Bitcoin adopts a system, changing it later could take years to implement.

However, as noted in the Coinbase report, while quantum risk is not urgent, ignoring it now could become a significant problem later.