Quantum Threat Looms: 6.9 Million Bitcoin Vulnerable, Researcher Warns
Quantum computers could crack nearly 7 million Bitcoin wallets—and the clock is ticking.
The Looming Break
Forget password hacks. This is about math. The encryption shielding a massive chunk of Bitcoin's wealth relies on a problem quantum machines are built to solve. Researcher analysis puts a target on roughly 6.9 million BTC. That's not just loose change sitting in a couch; it's a significant portion of the entire system's value, suddenly up for grabs if the tech matures faster than defenses.
The Race No One Wants to Win
Developers aren't sleeping. Post-quantum cryptography is the buzzword, the armor being forged against a weapon that doesn't fully exist yet. The entire blockchain premise—immutable, secure ledgers—hits a existential crisis if its foundational security gets bypassed. Upgrading a live, trillion-dollar network, however, is like changing the engines on a plane mid-flight. Every wallet, every exchange, every cold storage device needs to get the memo and the patch.
A Hedge Fund Manager's Dream (or Nightmare)
Talk about a volatility catalyst. The mere credible advance of quantum capability could trigger panic sells from the vulnerable, while the 'quantum-resistant' coins pump on speculative frenzy—a trader's paradise built on collective anxiety. It's the ultimate stress test, one where failing means rewriting the rules of digital ownership. The irony? The very institutions that once dismissed crypto are now probably funding the quantum research that might break it. Finance, ever the circular firing squad.
So the countdown isn't just about bits and qubits. It's a multi-billion dollar game of chicken between creation and destruction. Will the patch get deployed in time, or will the future of money get hacked by the future of computing? The market, as usual, will price in the fear long before the answer arrives.
Why ‘Only 10,000’ Bitcoin Are The Wrong Estimate
Pruden’s Core objection to the “only 10k BTC” framing is definitional. In his thread, he argues quantum vulnerability extends well beyond old-style pay-to-public-key (P2PK) outputs and includes “any address that has signed a transaction once (and left residual funds there),” because the public key becomes visible on-chain once a spend is signed. In that model, coins left behind in those UTXOs could be vulnerable to an attacker able to derive a private key from a known public key.
He points to a “constantly updated tracker” run by Project Eleven listing 6,910,186 BTC as quantum-vulnerable, and cites Chaincode Labs’ technical report on post-quantum threats to Bitcoin as a cross-reference.
Pruden also singles out Satoshi Nakamoto’s presumed holdings as a large, dormant target surface. “The entity believed to be Satoshi alone holds 1,096,152 BTC across 21,924 addresses. All vulnerable,” he wrote, framing those coins as exposed under his broader definition.
Carter, responding to coverage circulating around the CoinShares number, said: “re that number of ‘only 10k quantum-vulnerable BTC’ you are seeing reported today… as much as I respect Chris and his work at Coinshares, he’s wrong on this one.”
Pruden situates the Bitcoin debate inside a wider shift among large tech companies and security institutions toward post-quantum planning. He cites a Google blog post by Hartmut Neven and Kent Walker that characterizes post-quantum cryptography as an urgent, systemic transition requiring coordinated action and accelerated adoption.
He also references a Google research result suggesting breaking RSA-2048 may require “~1 million noisy qubits,” lower than earlier estimates, and argues this compresses perceived timelines — even if Bitcoin uses ECDSA rather than RSA. To reinforce the uncertainty, Pruden quotes prominent theoretical computer scientist Scott Aaronson warning against complacency around Shor-vulnerable systems:
“On the other hand, if you think Bitcoin, and SSL, and all the other protocols based on Shor-breakable cryptography, are almost certainly SAFE for the next 5 years … then I submit that your confidence is also unwarranted. Your confidence might then be like most physicists’ confidence in 1938 that nuclear weapons were decades away, or like my own confidence in 2015 that an AI able to pass a reasonable Turing Test was decades away… The trouble is that sometimes people, y’know, do that.”
Pruden’s conclusion from that framing is less about predicting a date and more about avoiding a planning regime built on “it’ll be slow.”
Pruden argues the CoinShares post underestimates the operational reality of a post-quantum transition for an already-deployed, decentralized system. He highlights the need to migrate “millions of distributed keys,” the lack of a centralized authority, and the fact that asset ownership is enforced purely by digital signatures, with “no fallback.”
He also cites peer-reviewed research claiming “the BTC blockchain WOULD have to shut down for 76 days” to process migration transactions for the existing UTXO set in a best-case scenario — a datapoint meant to stress that even a distant threat can demand near-term engineering and governance work.
Pruden further criticizes what he calls an appeal to authority in citing a hardware-wallet executive as evidence quantum is far away, arguing vendors may have incentives to downplay urgency if quantum-resistant signatures would obsolete existing devices.
At press time, BTC traded at $69,050.
