Adam Back: Bitcoin Faces No Quantum Risk For Next 20–40 Years

Adam Back says Bitcoin faces no meaningful quantum threat for at least the next 20–40 years, adding that NIST-approved post-quantum standards can be adopted in time.

Adam Back, the cryptographer and cypherpunk cited in the Bitcoin white paper, said Bitcoin is unlikely to face a meaningful threat from quantum computing for at least two to four decades.

Responding to an X user on Nov. 15 who asked whether Bitcoin (BTC) is at risk, Back wrote that “probably not for 20–40 years,” adding that there are already post-quantum encryption standards approved by the National Institute of Standards and Technology (NIST) that Bitcoin could implement “long before cryptographically relevant quantum computers arrive.”

The discussion began with a user posting a video of Canadian-American venture capitalist and entrepreneur Chamath Palihapitiya, who predicted that the quantum threat to Bitcoin would become a reality in two to five years. He noted that to break SHA-256 — the encryption standard that Bitcoin relies on — quantum computers would need about 8,000 qubits.

During a mid-April interview with Cointelegraph, the cypherpunk suggested that quantum computing pressure may reveal whether the blockchain’s pseudonymous creator is alive. Back explained that quantum computing could make the Bitcoin held by Satoshi Nakamoto vulnerable to being stolen, forcing him to move it to a new address to avoid losing access to his coins.

Related: What happens to Satoshi’s 1M Bitcoin if quantum computers go live?

Current quantum computers are either significantly too noisy to support encryption-breaking or severely lack in qubit count. For instance, the Caltech neutral-atom array — the current qubit count record-holder — has as many as 6,100 physical qubits but is incapable of breaking RSA-2048, even though it is estimated to need only about 4,000 logical qubits.

The reason is that the 4,000-qubit rough estimate is an idealized model that assumes perfect local qubits — not accounting for real-world noise. Put simply, 4,000 qubits is the number required to run the encryption-breaking Beauregard’s Shor circuit on RSA-2048 in an error-free environment — this kind of qubit is called a logical qubit.

Less error-prone trapped-ion systems, such as Quantinuum’s Helios, reached 98 physical qubits, acting as 48 error-corrected logical qubits — meaning we get one usable qubit for every two physical qubits. Universal gate-based quantum computers reached 1,180 qubits with Atom Computing — the fi

Source: CoinTelegraph