Adam Back Clashes with Bitcoiner VC Over Quantum Computing Threat Claims

Bitcoin OG Adam Back just threw cold water on a venture capitalist's quantum computing doomsday scenario—and the crypto community is watching.

The Core of the Clash

The debate centers on whether quantum computers pose an imminent, existential threat to Bitcoin's cryptography. The VC's warning sparked fears, but Back's rebuttal cuts straight to the hype. He argues the timeline is wildly exaggerated and the Bitcoin network wouldn't just sit idle.

Why the Timeline Matters

Experts point out that a quantum machine powerful enough to crack Bitcoin's SHA-256 isn't sitting in a lab somewhere. Development is measured in decades, not years. That gives the protocol—and its army of developers—ample time to adapt. It's a classic case of long-term risk versus short-term FUD.

The Pragmatic Defense

Back's stance highlights a key Bitcoin ethos: antifragility. The network has survived countless predicted deaths. The response to a real quantum threat wouldn't be panic—it'd be a coordinated, backward-compatible upgrade. Think of it as a cryptographic vaccine, developed before the disease becomes a pandemic.

The Finance Jab

Meanwhile, traditional finance still struggles with basic database reconciliation—so maybe quantum-breaking Bitcoin isn't their most pressing issue.

The takeaway? Fear sells, but code adapts. This public spat underscores a healthy ecosystem stress-testing its own assumptions, while the rest of the market just chases the next narrative.

Blockstream CEO criticizes Carter over quantum risks narratives

In his post, the Blockstream CEO mentioned that the bitcoin community is not denying the need for research and development of protections against potential quantum computing threats. He highlighted that the work is currently being carried out, noting that they are doing it ‘quietly.’ However, Carter fired back, noting that many Bitcoin developers are still in denial about the risk of quantum computing affecting Bitcoin and making its encryption vulnerable.

While Castle Island Ventures’ investment recently became a topic of discussion with the Bitcoin community, Carter first disclosed the investment in a Substack post on October 20. “I disclosed this in the first sentence of my main article on quantum. Can’t get more transparent than that,” Carter said. Carter highlighted that he invested in the work being done by Project Eleven because its CEO, Alex Pruden, “quantum pilled” him. “I became extremely concerned about quantum threats to blockchains. I put capital behind my convictions, always have,” he said.

Carter added that he knew that he WOULD suffer criticisms such as the Blockstream CEO’s, and that was why he was absolutely clear about his financial exposure in the project. Carter raised several points why he feels quantum computing could pose a risk to Bitcoin, highlighting governments’ planning for a post-quantum world, Bitcoin itself being a bug bounty for quantum supremacy, and the increasing amount of investment in quantum firms.

Bitcoin community divided over the seriousness of the issue

Nic Carter is not the only popular Bitcoin figure to have recently increased his warnings about the potential threat that quantum computing could pose to Bitcoin. Capriole Investments founder Charles Edwards warned in a post on X on Thursday. He mentioned that a quantum computer could break Bitcoin in the next 2-9 years. He noted that if the security is not upgraded, there is a likelihood that it will happen in the next 4-5 year range, noting that it is the time frame that all experts have predicted.

“Don’t believe the naysayers. We have already entered the Quantum Event Horizon: the frontier risk of a quantum hack is the same amount of time away as upgrade consensus and roll-out. We must act in 2026. Let’s finish and deploy BIP 360,” Edwards added. Meanwhile, others have shown little or no concern about the issue at hand. An example is Kevin O’Leary, who recently mentioned that using a quantum computer to break Bitcoin wouldn’t be the most effective use of the technology.

He highlighted that the technology could be put to better use in areas like AI-driven medical research, which he describes as a more valuable use. Meanwhile, the Blockstream CEO noted that it is good for Bitcoin to be quantum-ready, noting that it won’t be a threat for the next few decades, as the technology is still too early and has research and development issues.

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