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 committee that includes 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 today’s blockchains remain secure, a future “fault-tolerant quantum computer” must increasingly begin to encrypt and is now increasingly capable of breaking and encrypting.
In recent months, concerns about quantum risk have moved further into the mainstream. Google researchers have published estimates suggesting that a sufficiently advanced quantum computer could one day break Bitcoin’s cryptography.
Major crypto-ecosystems have already begun mapping out 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 wallets.
The report emphasizes that current quantum machines are far from powerful enough to crack the cryptography that underpins Bitcoin, Ethereum and other networks. Breaking standard encryption would require large computational overhead, a milestone still considered a major engineering challenge.
Still, the authors caution against complacency.
“We have high confidence that a large-scale, fault-tolerant quantum computer will eventually be built,” the report said, adding that the timeline is uncertain but “clearly on the horizon.”
That uncertainty is exactly the problem, with estimates ranging from “a few years to a decade or more” and no reliable way to predict breakthroughs.
That urgency is reflected in guidance from the US National Institute of Standards and Technology (NIST), which recommends migrating to quantum-resistant cryptography by 2035, a timeline that the report suggests may even turn out to be optimistic.
“Waiting for urgency is not a good idea,” the Coinbase paper says, noting that transitions across blockchains, wallets and exchanges can take years to execute securely.
Some assets may be more vulnerable than others. For example, Bitcoin wallets that have already disclosed their public keys may be targeted, while those that are still protected behind hash functions may be more secure in the short term.
The good news: Quantum-resistant cryptography (PQC) already exists and is being standardized by NIST.
The bad news: It’s not an easy trade.
Post-quantum digital signatures could be tens to hundreds of times larger than current ones, which could dramatically increase blockchain data costs and reduce throughput. One estimate in the report suggests that replacing today’s signatures with quantum-secure alternatives could expand 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 upgrade.
Rather than a single solution, the report outlines several transition strategies, including hybrid systems that combine existing cryptography with post-quantum updates or allow a gradual switch when needed.
For now, the authors recommend flexible approaches that avoid sacrificing current security or performance while enabling a quick upgrade later.
“The time to start preparing for it is now,” the report concludes.
Read more: Solana’s preparedness for quantum threats reveals a harsh trade-off: security vs. speed
