Quantum computing threatens Bitcoin’s cryptographic security

Coinbase’s head of global investment research, David Duong, has expressed deep concerns over Bitcoin’s long-term security and sustainability due to the advancements in quantum computing.

Bitcoin is often characterized by its high degree of security, mainly due to its underlying blockchain technology. However, experts caution that a new threat powered by quantum computing could pose significant risks to cryptography through cryptographically relevant quantum computers (CRQCs).

Quantum computing threatens Bitcoin’s cryptographic security 

David Duong, the head of global investment research at Coinbase, cautioned that advances in quantum computing are raising concerns about the long-term sustainability of Bitcoin. The Coinbase executive cited a previous concern highlighted by BlackRock in its amended prospectus for the iShares Bitcoin Trust ETF (IBIT), filed with the SEC on May 9, 2025. 

BlackRock highlighted in the filings that the cryptographic infrastructure supporting Bitcoin could become “flawed or ineffective” due to the development of quantum computing technology. The investment fund explained that quantum computing is still in its early stages of development and, therefore, difficult to project its ultimate impact on the broader blockchain infrastructure. 

The report also noted that quantum computing applications could advance to the point where they possess the ability to compromise Bitcoin’s security by allowing malicious attackers to infiltrate its security and compromise wallets with Bitcoin holdings.

According to Duong, quantum computing will necessitate upgrades to many of the cryptographic systems currently in use. He also explained that traditional finance may be among the most affected sectors due to its overreliance on closed systems. Duong said open protocols like Bitcoin and Ethereum are also preparing for the effect of quantum computing.

Duong said that cryptographically relevant quantum computers (CRQCs) could gain the capability to run Shor’s and Grover’s algorithms, which may destabilize Bitcoin’s cryptographic infrastructure. He emphasized that the new technology brings two types of risks into scope, which are likely to compromise Bitcoin’s SHA-256 for the proof-of-work mining processes and the Elliptic Curve Digital Signature Algorithm (ECDSA) that powers transaction signatures.

The Coinbase researcher stated that cryptographically relevant quantum computers could potentially break the “cryptographic security of private keys” and allow malicious actors to steal crypto assets from vulnerable addresses. He added that other attacks could infiltrate Bitcoin’s mining infrastructure by mining blocks more efficiently. 

32.7% of BTC’s supply is at risk of long-range attacks

Duong added that quantum mining is a lower-priority concern for now, but signature migration carries immediate risks. He said that initial threats span “into two dimensions: long-range attacks against outputs whose public keys are already exposed onchain, and short-range attacks that could front-run spends as public keys appear in the mempool.”

According to the researcher, approximately 32.7% of Bitcoin’s supply, or roughly 6.51 million BTC, is vulnerable to long-range attacks due to the reuse of addresses and script types that reveal public keys onchain. He highlighted such scripts, including Pay-to-Public-Key (P2PK), bare multisig (P2MS), and Taproot (P2TR). 

He also mentioned that every output is vulnerable to short-range attacks at the time of spending, which prompts the need to migrate to quantum-resistant signatures, despite the low possibility of an attack.

The warning comes as scientists continue to advance the development of quantum computers. Quantum computers utilize quantum mechanics to process data in more advanced ways than traditional computers.

Pierre-Luc Dallaire-Demers, a quantum computing scientist at Google, stated in October 2025 that these advanced computers will be able to break Bitcoin’s cryptography in under five years.

Although quantum computing is still in its infancy, a recent report from Cryptopolitan noted that Google claimed a breakthrough in AI and quantum computing. The technology conglomerate stated that it had developed a computer algorithm that suggests potential directions for practical applications of quantum computing. According to the report, Google said the algorithm will generate unique data for use with AI.

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