A new report commissioned by Coinbase sounds a cautious, but urgent, alarm: Quantum computing won’t break crypto tomorrow, but the industry can’t afford to wait.
The 50-page paper, authored by an independent advisory board made up of prominent cryptographers and academics such as Dan Boneh of Stanford University, Justin Drake of the Ethereum Foundation and Sreeram Kannan of Eigen Labs, concludes that while current blockchains remain secure, a future “fault-tolerant quantum computer” capable of breaking widely used encryption is increasingly plausible, and preparation must begin now.
In recent months, concerns about quantum risk have become increasingly widespread. Google researchers have published estimates suggesting that a sufficiently advanced quantum computer could one day break Bitcoin’s cryptography.
Major crypto ecosystems have already started crafting their responses. The Ethereum Foundation has proposed new types of digital signatures designed to be secure against quantum computers, while Solana and others are experimenting with quantum-resistant wallet designs.
The report highlights that current quantum machines are nowhere near powerful enough to crack the cryptography that underpins Bitcoin, Ethereum and other networks. Breaking standard encryption would require a huge computational load, a step still considered a major engineering challenge.
The authors nevertheless warn against complacency.
“We are confident that a large-scale, fault-tolerant quantum computer will ultimately be built,” the report said, adding that the timeline is uncertain but “clearly on the horizon.”
This uncertainty is precisely the problem, with estimates ranging from “a few years to a decade or more” and no reliable way to predict progress.
The urgency is reflected in guidance from the U.S. National Institute of Standards and Technology (NIST), which recommends migrating to quantum-resistant cryptography by 2035, a timeline that the report suggests may even prove optimistic.
“Waiting until this is urgent is not a good idea,” the Coinbase document states, noting that transitions between blockchains, wallets, and exchanges could take years to execute securely.
Some assets may be more vulnerable than others. For example, Bitcoin wallets that have already revealed their public keys could be targeted, while those still protected behind hash functions could be more secure in the short term.
The good news: Quantum resistance cryptography (PQC) already exists and is being standardized by NIST.
The bad news: It’s not an easy trade.
Post-quantum digital signatures may be tens or even hundreds of times larger than current signatures, which could significantly increase blockchain data costs and reduce throughput. One estimate in the report suggests that replacing current signatures with quantum-proofing alternatives could increase block sizes by up to 38 times.
There are also usability challenges, from migrating millions of wallets to deciding what to do with “lost” or inactive funds that never get upgraded.
Rather than a single solution, the report outlines several transition strategies, including hybrid systems that combine existing cryptography with post-quantum updates or allow for incremental change if necessary.
For now, the authors recommend flexible approaches that avoid sacrificing current security or performance while allowing rapid upgrade later.
“Now is the time to start preparing,” the report concludes.
Read more: Solana’s preparation for quantum threats reveals a difficult tradeoff: security versus speed
