Cypherpunk and cryptographer Adam Back stated on X on Saturday that Bitcoin is unlikely to face any significant quantum threat for at least the next 20 to 40 years. Back, who invented Hashcash — the proof-of-work algorithm later adopted by Bitcoin — was responding to a user sharing a video concern that quantum computers could break Bitcoin’s cryptography within two to five years.
In his post, Back noted that quantum-secure digital signatures already exist, pointing to SLH-DSA, a scheme standardized by NIST last year. He was replying to a user, who referenced comments by venture capitalist Chamath Palihapitiya, who argued that quantum machines could defeat Bitcoin’s SHA-256 encryption once they reach roughly 8,000 qubits.
Bitcoin can add over time, as the evaluation continues and be quantum ready, long before cryptographically relevant quantum computers arrive.
Quantum risk discussions have circulated in the Bitcoin community for years. Analysts generally say the network would have significant time to migrate to new cryptographic standards before quantum machines reach levels capable of breaking modern encryption.
Previous Concerns and Expert Opinions
Earlier, in September, Solana founder Anatoly Yakovenko said there is a “50/50 chance” that quantum computing could break Bitcoin cryptography by 2030. Michael Saylor also echoed long-term risks, noting that quantum computers could eventually crack Bitcoin, though likely in “10–20 years,” positively adding that the network would upgrade as needed.