TL;DR

Duong warned “Q-day” could target Bitcoin’s ECDSA signatures and SHA-256 proof-of-work, not only cold wallets.
He said quantum computers could both steal funds by breaking signatures and mine blocks faster, though mining is lower priority for now and disrupt its security model overall.
Duong sees today’s machines as too small to be imminent, but urges post-quantum signature migration amid debate between Adam Back and Charles Edwards as teams stay vigilant.

Crypto’s quantum anxiety is shifting from theory to governance, and Coinbase investment research head David Duong wants the industry to widen its scope. Writing in a LinkedIn post  he said the risk is not limited to cold wallets and stolen keys. “Q-day” could pressure Bitcoin’s core security assumptions, because cryptographically relevant machines may run Shor’s and Grover’s algorithms against signatures and hashing. In his framing, Bitcoin rests on ECDSA for transaction signatures and SHA-256 for proof-of-work, so a quantum leap could touch both pillars at once across crypto circles.

Two Quantum Threats: Keys and Mining Power

Duong argued quantum computers pose two distinct threats to Bitcoin, one aimed at private keys and another at mining efficiency. If signatures can be undermined, attackers could reveal user keys and steal funds from vulnerable addresses. Separately, if quantum systems mine blocks far more efficiently, they could disrupt Bitcoin’s economic and security model by changing how quickly blocks can be produced. The report notes quantum machines are theorized to perform exponentially faster than current computers, amplifying concern about future balance shifts. He called these risks separate, not interchangeable, and worth planning for now.

The mining angle matters because Bitcoin miners use computational power and energy to solve complex mathematical problems that add transaction blocks to the network. The report says a 51% attack requires massive computing power and could let one miner or a group control more than half of total mining power and manipulate the blockchain. Even so, Duong said quantum mining remains a lower-priority concern for now given scaling constraints, making signature migration the central issue for developers. He said the key priority is moving signatures to safer schemes before adversaries gain practical capability.

Duong also said he does not view quantum computing as imminent, because today’s machines are orders of magnitude too small to break Bitcoin’s cryptography. Still, he welcomed open-source vigilance on post-quantum migration paths. The report highlights a split: cypherpunk Adam Back has frequently argued the threat is overblown and likely decades away, while Capriole founder Charles Edwards is cited as calling it more imminent and urging earlier steps to keep the network secure. Back’s skepticism contrasts with Edwards’ urgency, keeping the conversation alive as the industry weighs timelines and upgrades in public forums now.

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Filed under: News - @ January 7, 2026 12:09 pm