As quantum computing technology advances, the long-term security of Bitcoin is entering "uncharted waters," warns David Duong, Global Head of Investment Research at Coinbase. Duong suggests that the cryptocurrency market is underestimating the risks posed by quantum computers.
While an immediate quantum attack isn't likely, Duong argues that the threat has evolved from a theoretical concern to a tangible structural risk, already affecting a significant portion of the Bitcoin supply. According to Duong, approximately one-third of all Bitcoin is vulnerable to long-range quantum attacks because the cryptographic output of the wallets holding these coins is publicly visible, making them susceptible to brute-force attacks. He noted that Bitcoin's long-term security may be entering a new regime as quantum computing advances.
Bitcoin relies on Elliptic Curve Cryptography (ECC) for encryption, which secures wallet addresses. However, algorithms like Shor's algorithm could theoretically be used by quantum computers to breach this encryption. This means that a quantum computer running Shor's algorithm could derive a private key from a public key, allowing an attacker to spend the coins held at that address. Wallets that maintain a record of past transactions are particularly vulnerable because their public keys have been exposed.
The risk extends beyond wallet hacks. Quantum computing's capacity to perform calculations at unprecedented speeds raises concerns about centralizing mining power and compromising Bitcoin's decentralized nature. Algorithms like Grover's could potentially accelerate mining processes, upsetting the balance of the Proof-of-Work (PoW) consensus mechanism that is integral to Bitcoin's operation.
The current quantum computing capabilities are not yet sufficient to disrupt Bitcoin's operations, but the concept of "quantum advantage," where quantum computers surpass classical ones, looms. Some researchers predict that quantum computers will be able to crack Bitcoin's cryptography within the next four to five years. BlackRock also flagged quantum computing as a risk factor in an amended prospectus for its iShares Bitcoin Trust back in May 2025.
Despite these challenges, the Bitcoin community remains committed to its foundational principles of immutability, decentralization, and verifiable costliness. Experts suggest proactive risk mitigation strategies, including post-quantum cryptography (PQC), hybrid systems, and privacy-focused assets. These strategies aim to combine classical and quantum-resistant encryption methods. One potential solution involves transferring Bitcoins to a new Pay-to-Public-Key Hash (p2pkh) address.
