Fears that quantum computing could one day break Bitcoin's cryptography have sparked heated debate, but Galaxy Digital's head of research, Alex Thorn, argues the narrative of an imminent existential crisis is overstated. While the risk is real—a sufficiently advanced quantum computer could theoretically derive private keys from exposed public keys—Thorn emphasizes the threat is recognized and actively being addressed by developers.
Analysis from security firm Project Eleven suggests roughly 7 million bitcoin (worth about $470 billion at recent prices) could be vulnerable under a "long exposure" definition where public keys have been revealed onchain. However, Thorn notes most bitcoin today is not immediately vulnerable, as funds are only at risk when public keys are exposed, such as from address reuse, certain custodial practices, or older address formats.
"The risk is real but recognized," Thorn told CoinDesk. "And the people best positioned to solve it are actively working on it." He positions the conversation between polarized views, acknowledging a meaningful future threat that warrants action but not one that outpaces Bitcoin's ability to respond.
Technical work is already underway to make Bitcoin "quantum-resistant." Efforts include introducing new address types using post-quantum cryptography, allowing users to migrate funds from vulnerable formats. Other proposals address edge cases like dormant coins, with ideas such as an "hourglass" approach to gradually restrict how such coins can be spent.
In a parallel development, BTQ Technologies announced the first working implementation of Bitcoin Improvement Proposal 360 (BIP 360) on its Bitcoin Quantum testnet. This system allows testing of quantum-resistant transaction structures and post-quantum signatures in a live environment. The upgrade introduces a method called Pay-to-Merkle-Root (P2MR), which commits transactions to a hashed set of conditions rather than exposing a public key upfront, reducing information available to a future quantum attacker.
However, BTQ President Christopher Tam highlighted the significant social hurdles. "It's the hardest part of the problem... It's a social problem," Tam told Decrypt, referring to the challenge of achieving consensus within Bitcoin's community for any major change. BTQ's strategy involves creating a separate "canary network"—the Bitcoin Quantum testnet—starting from a new genesis block rather than forking the existing Bitcoin state. This testnet already includes more than 50 miners and over 100,000 mined blocks.
Tam drew a comparison to the Y2K problem, noting that while everyone knew when Y2K would happen, the timing of a "Q-Day" (when quantum computers can break modern cryptography) is uncertain. "We know Q‑Day is going to happen at some point; the question is when," he said.
Thorn concluded that for investors, quantum risk should be monitored but not used as a blanket reason to avoid Bitcoin exposure, citing the network's track record of evolving in response to credible threats.
