Coinbase Exec Issues Stark Warning: Quantum Computing Puts 33% of Bitcoin Supply at Direct Risk – The Looming Crypto Security Crisis

Quantum computing isn't a distant sci-fi threat—it's a ticking time bomb for digital assets. A senior Coinbase executive just sounded the alarm, highlighting a critical vulnerability that could expose a third of all Bitcoin to potential theft.

The Quantum Countdown Has Begun

The core issue lies in encryption. Bitcoin's security, like much of the digital world, relies on cryptographic puzzles that today's computers find nearly impossible to crack. Quantum machines, operating on entirely different principles, threaten to solve these puzzles in minutes. The executive's warning zeroes in on a specific, chilling statistic: roughly 33% of the entire Bitcoin supply sits in wallets secured by encryption methods quantum computers are predicted to shatter.

Why a Third of All Bitcoin Is Suddenly in the Crosshairs

This isn't about hypothetical future coins. This is about existing, held Bitcoin. The vulnerability stems from wallet addresses generated using older, quantum-susceptible cryptographic signatures. If a bad actor with a powerful enough quantum computer targets these specific wallets, the funds could be drained. It's a silent, systemic risk baked into the blockchain's history—a risk that traditional financial auditors would have flagged as a 'material weakness' years ago.

The Race to Future-Proof Crypto

The industry isn't sitting idle. Developers are actively working on 'post-quantum cryptography'—new encryption standards designed to withstand quantum attacks. The transition, however, is a massive, complex undertaking that requires broad coordination across wallets, exchanges, and protocols. It's a multi-billion-dollar upgrade race against an advancing technological frontier.

For investors, the message is clear: the long-term thesis for Bitcoin and crypto isn't broken, but its foundation needs urgent reinforcement. The next major bull run might depend less on ETF approvals and more on successfully navigating this existential tech upgrade. After all, what's the point of digital gold if a new kind of vault-cracker is already in development? Sometimes the biggest threat to a volatile market isn't the regulators or the macro-economy—it's a physics lab on the other side of the planet.

Why Researchers Say a Third of Bitcoin Could Face Quantum Risk

At the center of the concern is what researchers often call “Q-day,” the point at which cryptographically relevant quantum computers become powerful enough to undermine today’s public-key systems.

Bitcoin relies on elliptic curve cryptography to secure wallets and on SHA-256 for mining.

Duong said quantum machines capable of running Shor’s algorithm could theoretically derive private keys from exposed public keys, allowing attackers to steal funds, while Grover’s algorithm could eventually make mining more efficient.

For now, signature security is viewed as the more urgent issue.

Based on on-chain data through block 900,000, Duong estimated that about 6.51 million BTC, or roughly 32.7% of the total supply, sits in address types that are more vulnerable to long-range quantum attacks.

These include legacy Pay-to-Public-Key outputs, bare multisig scripts, and some Taproot constructions where public keys are already visible on-chain. Satoshi-era coins are a well-known subset of this category.

In addition, Duong noted that every Bitcoin transaction briefly exposes a public key at the moment of spending, creating a short-range attack window if a sufficiently advanced quantum computer were ever available.

The warning builds on a broader industry debate that has intensified over the past year. On-chain analysts have highlighted that a large share of Bitcoin has remained dormant for long periods, with data showing more than 30% of supply unmoved for at least five years.

Analysts warn that #BTC quantum risk is political, and dormant $BTC on old addresses could be exposed to future attacks.#Bitcoin #QuantumComputinghttps://t.co/AYI0pMoZpW

Some researchers argue that those coins WOULD be the first targets if quantum attacks became feasible, while others say the larger challenge would be coordinating how the network responds.

Bitcoin’s Quantum Debate Moves From Theory to Planning

Not everyone agrees on the urgency, as in December, Blockstream CEO Adam Back pushed back against claims that Bitcoin faces an imminent quantum crisis, saying developers are already working quietly on long-term protections without inflaming markets.

@Blockstream CEO @adam3us has publicly pushed back against claims that Bitcoin faces an imminent threat from quantum computing.#Bitcoin #Quantumhttps://t.co/8Xsi3zt95n

Venture investor Nic Carter disagreed, arguing that too many in the ecosystem remain in denial and pointing to government preparations and rising investment in quantum firms as signs the risk deserves more attention.

The divide extends to timelines, with Capriole Investments founder Charles Edwards warning that quantum threats could materialize within a decade without upgrades, while others place the risk further out.

Strategy executive chairman Michael Saylor has taken a more optimistic view, saying that a quantum breakthrough would ultimately “harden” Bitcoin as active coins migrate to new standards and inaccessible coins remain frozen, reducing effective supply.

Despite differing opinions, preparations are underway. Bitcoin developers have discussed post-quantum signature schemes, and the U.S. National Institute of Standards and Technology finalized several quantum-resistant standards in 2024.

Implementing them on Bitcoin would require broad consensus and likely a hard fork, a process complicated by inactive wallets and the network’s decentralized governance.

Researchers continue to warn that adversaries may already be collecting blockchain data today in anticipation of future breakthroughs.