Bitcoin should prepare now for potential quantum threat, says Adam Back

Blockstream CEO Adam Back, an early pioneer of the crypto movement, said Bitcoiners should begin building quantum-resistant solutions now, even though the threat is still decades away.

Speaking at Paris Blockchain Week on Tuesday, Back said quantum computing “still has a lot to prove,” describing current systems as largely “lab experiments.” He added that he has followed the field for more than 25 years and that progress has been “incremental.”

Back said Bitcoin should prepare by using “optional upgrades” that would allow migration to quantum-resistant cryptography if needed. He argued that this approach is the “safest” way to respond to a potential future risk.

Why quantum risk matters for crypto security

Concerns that quantum computers could eventually break blockchain cryptography have contributed to broader industry fears that attackers could compromise crypto wallets, potentially destabilizing markets.

Back previously said in November that the quantum threat is 20 to 40 years away. Earlier this month, he told Bloomberg that today’s quantum computers are slower than calculators.

Despite the timeline, Back said Blockstream has a dedicated quantum team researching potential threat vectors to the Bitcoin network.

Blockstream work on quantum-resistant components

Back said part of Blockstream’s efforts has included implementing hash-based signatures on Blockstream’s Bitcoin layer-2 Liquid Network.

He also said the Taproot protocol could support alternative signature schemes on the Bitcoin network without affecting current users.

“Preparation is key. Making changes in a controlled way is far safer than reacting in a crisis,” Back said.

Research suggesting the timeline could be shorter

Back referenced recent claims from Google and the California Institute of Technology, where researchers said functional quantum computers could arrive sooner than expected and that far less computing power may be required to break cryptography than previously thought.

Google has said quantum computers could potentially break Bitcoin’s cryptography as quickly as nine minutes, enabling an “on-spend” attack.

Back’s view on an urgent response

Asked what would happen if the quantum threat arrives earlier than anticipated, Back said Bitcoin developers would “act quickly.”

He pointed to past experience, saying: “We’ve seen that before — bugs have been identified and fixed within hours. When something becomes urgent, it focuses attention and drives consensus.”

Proposal to freeze quantum-vulnerable Bitcoin draws backlash

On Tuesday, Bitcoin developer Jameson Lopp and five other crypto security researchers introduced a proposal to freeze quantum-vulnerable Bitcoin, including Satoshi Nakamoto’s $81.9 billion stash, to prevent theft once quantum computers become functional.

The proposal was met with criticism from several figures in the Bitcoin community. Developer and researcher Mark Erhardt described it as “authoritarian and confiscatory.”

Phil Geiger, head of business development at Metaplanet, said: “We have to steal people’s money to prevent their money from being stolen.”