It has been discovered by Google researchers that significantly fewer quantum resources are required to break RSA encryption, the same technology used to protect cryptocurrency wallets, than was previously believed.
A newly released research paper by Google has raised concerns among Bitcoin enthusiasts, as a startling discovery was shared by the company’s quantum team. It was revealed that the RSA encryption securing assets such as bank accounts and Bitcoin wallets could potentially be broken using 20 times fewer quantum resources than earlier projections had indicated.
It was noted by Google Quantum Researcher Craig Gidney that an understanding of the cost of quantum attacks on vulnerable cryptosystems is essential for planning a shift toward quantum-resistant cryptographic systems. In a 2019 study co-authored by Gidney and Ekerå, it had been estimated that factoring 2048-bit RSA integers could be accomplished within eight hours using a quantum computer equipped with 20 million noisy qubits. In the newly published paper, Gidney reported that the qubit requirement has now been significantly lowered.
It was argued by Gidney that the factoring of a 2048-bit RSA integer could be achieved in under a week by a quantum computer utilizing fewer than one million noisy qubits.
In an official blog post, the Google researcher stated that the latest finding represents a 20-fold reduction in the required number of qubits compared to their earlier estimate.
However, such a development is not expected to occur in the immediate future. For perspective, IBM’s Condor, currently the most advanced quantum computer, operates with 1,121 qubits, while Google’s Sycamore functions using only 53 qubits. As a result, cryptocurrency holdings remain secure—for the time being. Nevertheless, it is the technological trajectory that raises concern, suggesting a direction that should prompt heightened awareness among crypto asset holders.
According to Google, the advancement has been made possible through two key factors: improved algorithms and enhanced error correction techniques. On the algorithmic front, researchers discovered a method to perform modular exponentiation—a core component of encryption—at twice the previous speed. Meanwhile, the progress in error correction was achieved by introducing an additional layer, allowing the logical qubit density to be tripled, which enabled a greater number of effective quantum operations to be packed into the same physical qubit space.
A technique known as “magic state cultivation” was also implemented, which involves enhancing the strength and reliability of special quantum components referred to as T states. This approach enables quantum computers to execute complex operations with greater efficiency while minimizing the consumption of additional resources, ultimately reducing the workspace required for fundamental quantum processes.
Why Quantum Computers Should Matter to Bitcoin Holders
Bitcoin’s security is based on elliptic curve cryptography, which is grounded in mathematical principles similar to those used in RSA. If quantum computers are able to compromise RSA sooner than previously projected, the timeline for Bitcoin’s vulnerability may also be accelerated. Although the cryptocurrency utilizes 256-bit encryption, which is more robust than the RSA keys examined by Google, the advantage is not as substantial as one might expect—particularly in the context of exponentially advancing quantum capabilities.
Efforts are already being undertaken by experts to explore methods of utilizing quantum technology to potentially compromise Bitcoin’s security.
A quantum computing research initiative known as Project 11 introduced a Bitcoin bounty valued at nearly $85,000 for individuals capable of breaking even a simplified form of Bitcoin’s encryption through the use of a quantum computer. The challenge involves testing encryption keys ranging from 1 to 25 bits—a small fraction of Bitcoin’s 256-bit encryption—but the purpose is to monitor advancements in quantum decryption capabilities.
It was stated by Project 11, upon announcing their challenge, that Bitcoin’s security depends on elliptic curve cryptography, and that quantum computers operating Shor’s algorithm will inevitably be capable of breaking it. The initiative, they explained, is intended to evaluate the urgency of the potential threat.
The broader security consequences go well beyond cryptocurrency. RSA and comparable encryption systems form the foundation of secure communications worldwide, encompassing sectors such as banking and digital authentication. It was highlighted by Google that potential adversaries may already be gathering encrypted information with the intent to it in the future, once quantum computing capabilities become available. As a result, preparations are actively being made to address this approaching reality.
It was stated by Google that traffic within Chrome and internal systems has already been encrypted, and that a transition to the standardized version of ML-KEM was implemented as soon as it became accessible.
Post-quantum cryptography standards were issued last year by the National Institute of Standards and Technology (NIST), with a recommendation that vulnerable systems be phased out after 2030. However, based on Google’s latest research, it has been suggested that this timeline may require a faster implementation.
Plans have been outlined by IBM to develop a 100,000-qubit quantum computer by 2033, in collaboration with the University of Tokyo and the University of Chicago. Meanwhile, Quantinuum has set a goal to introduce a fully fault-tolerant quantum computer by 2029. In light of Google’s recent discoveries, these timelines have gained increased relevance and urgency.
Another critical factor to address is the duration for which quantum machines can operate without disruption. The theoretical million-qubit system described by Google would be required to function continuously for several days, sustain very low error rates, and execute billions of operations in a highly coordinated manner. At present, quantum computers are only capable of maintaining coherence for a few minutes, so for now, there remains no immediate cause for alarm.
The quantum threat is not yet imminent, but its advancement is progressing more rapidly than initially anticipated. In response, efforts have already been initiated within the crypto community to develop quantum-resistant solutions. A quantum-secure vault utilizing hash-based signatures has been introduced by Solana developers, while Ethereum co-founder Vitalik Buterin has suggested that the codebases of existing blockchains be forked as a protective measure against potential quantum vulnerabilities.
It appears increasingly probable that an anti-quantum hard fork will be implemented at some point in the future, well before any successful quantum-based breach of the Bitcoin blockchain is carried out—hopefully.
