Google Warns Quantum Computing Could Break Bitcoin Security by 2029

Google has issued a warning that large-scale quantum computers may be capable of breaking the elliptic curve cryptography that secures Bitcoin and other digital assets sooner than previously estimated. In a whitepaper published on March 31, 2026, the company indicated that future quantum computers could compromise these systems using fewer qubits and gates than earlier projections suggested.

The findings suggest that the encryption currently used to keep confidential information secure could be broken by a large-scale quantum computer in the coming years. Google has specifically highlighted a 2029 timeline, urging banks, governments, and technology providers to upgrade their security systems before current cryptographic standards become obsolete.

Quantum Vulnerabilities and the 2029 Timeline

The research, led by Ryan Babbush, Director of Research for Quantum Algorithms, and Hartmut Neven, VP of Engineering at Google Quantum AI, focuses on the threat posed by cryptographically relevant quantum computers (CRQCs). These machines use the physics of quantum mechanics to perform sophisticated mathematical calculations that are impossible for classical computers.

According to the whitepaper, these future machines could neutralize the cryptographic protections of blockchains. To mitigate these risks, Google is recommending that the cryptocurrency community transition to post-quantum cryptography (PQC), which is designed to be resistant to quantum attacks.

Google stated that it is working alongside other industry entities to prepare for this transition. These collaborators include the Ethereum Foundation, Coinbase, and the Stanford Institute for Blockchain Research.

Responsible Disclosure and Mitigation

To prevent the research from providing a roadmap for bad actors, Google engaged with the U.S. Government to develop a method of describing these vulnerabilities via a zero-knowledge proof. This allows the vulnerabilities to be verified by relevant parties without exposing the exact mechanisms that could be exploited.

Google has been involved in the transition to post-quantum cryptography since 2016. The company is now urging other research teams to adopt similar responsible disclosure practices to ensure global security remains intact as quantum capabilities advance.

Technical Challenges of Quantum Computing

Despite the projected threat, large-scale quantum computing remains a nascent technology with significant engineering hurdles. Current systems are often too small to perform the complex tasks that pose a threat to global encryption.

The development of these systems requires extreme conditions and high precision, including:

• The use of massive amounts of helium to cool quantum systems to near-absolute zero temperatures.
• Extensive periods of work, sometimes lasting weeks, to align lasers.

Google, Microsoft, and various universities in the United States and the United Kingdom continue to build systems to harness these capabilities, while simultaneously warning that the window for upgrading existing encryption is closing.

Market Implications for Digital Assets

The prospect of quantum computers neutralizing the security of digital assets has raised concerns regarding the potential for significant price volatility in Bitcoin. Because the security of the network relies on the difficulty of reversing certain mathematical functions, the ability of a quantum computer to solve these functions quickly would undermine the fundamental trust in the blockchain’s integrity.

The transition to post-quantum cryptography is presented as the primary solution to maintain the stability and security of the cryptocurrency ecosystem before the projected 2029 threshold.