Adam Back Dismisses Quantum Threat to Bitcoin as Overstated
17.11.2025
News / Economy / Analytics
Quantum systems capable of breaking the cryptography of the first cryptocurrency are unlikely to emerge for another 20-40 years, according to Blockstream co-founder and cypherpunk Adam Back.
The expert did not rule out the possibility that such computers may never materialize.
The discussion began with a statement from venture investor Chamath Palihapitiya, who believes that cryptographically significant computing could arrive in two to five years. He estimates that breaking Bitcoin’s SHA-256 algorithm would require about 4000 stable logical qubits.
Back disagreed, pointing to existing quantum-resistant algorithms such as the standardized NIST in 2024 SLH-DSA.
He believes the digital gold network has ample time to gradually implement such solutions and “be quantum ready long before practically significant quantum computers arrive.”
Earlier, analyst Willy Woo expressed a similar view, suggesting the threat would not become real before 2030.
In December 2024, Back stated that advancements in quantum computing would strengthen Bitcoin rather than destroy it. He is among the experts who consider the threat from this technology to be exaggerated.
Szabo linked the risks to the growing volume of arbitrary data in the first cryptocurrency’s blockchain — referring to Ordinals, Runes, and BRC-20 transactions, which contain images, videos, and other non-financial content.
Debate on this began with the controversial update Bitcoin Core v30. It increased the data transmission limit in OP_RETURN outputs from 80 to 100,000 bytes. Critics pointed to potential risks of spreading illegal content.
The expert did not rule out the possibility that such computers may never materialize.
The discussion began with a statement from venture investor Chamath Palihapitiya, who believes that cryptographically significant computing could arrive in two to five years. He estimates that breaking Bitcoin’s SHA-256 algorithm would require about 4000 stable logical qubits.
Back disagreed, pointing to existing quantum-resistant algorithms such as the standardized NIST in 2024 SLH-DSA.
He believes the digital gold network has ample time to gradually implement such solutions and “be quantum ready long before practically significant quantum computers arrive.”
Earlier, analyst Willy Woo expressed a similar view, suggesting the threat would not become real before 2030.
In December 2024, Back stated that advancements in quantum computing would strengthen Bitcoin rather than destroy it. He is among the experts who consider the threat from this technology to be exaggerated.
More Serious Risks Exist
Digital gold is vulnerable to legal attacks from governments and corporations, according to renowned cryptographer and smart contract pioneer Nick Szabo.“To consider Bitcoin or any other blockchain as an impregnable bastion of anarcho-capitalism against any state intervention is sheer madness,” he wrote.The expert explained that each cryptocurrency has a “legal attack surface,” which allows governments to influence the network’s operation through miners, node operators, and wallet providers in jurisdictions with the rule of law.
Szabo linked the risks to the growing volume of arbitrary data in the first cryptocurrency’s blockchain — referring to Ordinals, Runes, and BRC-20 transactions, which contain images, videos, and other non-financial content.
Debate on this began with the controversial update Bitcoin Core v30. It increased the data transmission limit in OP_RETURN outputs from 80 to 100,000 bytes. Critics pointed to potential risks of spreading illegal content.
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