Oxford Quantum Circuits (OQC) announced on June 5 that it aims to revolutionize the scalability of quantum computing. By 2028, OQC plans to reach 200 logical qubits, and by 2034, the goal is more ambitious: 50,000 logical qubits in quantum computers. 

These figures, according to the report by the British company spun out of Oxford University, exceed the efficiency of converting physical qubits to logical qubits by more than 10 times compared to current approaches.

As described by Oxford Quantum Circuits, the goal will be to use quantum computing for fraud detection, cybersecurity, and the development of new drugs, prioritizing sectors such as finance, defense, and the arts. 

Authorities weigh in on quantum and Bitcoin

Adam Back, co-founder of Blockstream, a company developing technologies linked to Bitcoin, noted last December that breaking ECDSA would require a quantum system with “300 million physical qubits ” and error correction that currently doesn’t exist, estimating that at the current rate this could take about 50 years, according to Back. 

Since Back refers to the number of physical qubits, it is necessary to approximate a notion of how many of those qubits are necessary to build a logical qubit (those indicated by the OQC report).  

An April 2025 analysis by the specialist site Post Quantum explains that converting physical qubits to logical qubits is computationally expensive: each logical qubit may require hundreds or thousands of physical qubits.

For example, according to data from Post Quantum, a Google prototype logical qubit used 49 physical qubits to encode a single logical qubit, while in less efficient systems this ratio reaches 1,000 physical qubits per logical qubit.  

Using that last figure of “1,000 physical qubits per logical qubit ” as a reference, Oxford Quantum Circuits, with its “10 times more efficient” technology, might need around 100 physical qubits per logical qubit, meaning that 50,000 logical qubits would be equivalent to roughly 5 million physical qubits (50,000 × 100)  a far cry from the 300 million Back reckons are needed to break ECDSA. 

In line with Back's vision, a study from the University of Sussex reported calculated that 13 million physical qubits would be needed to compromise Bitcoin encryption in one day, a number that, using the optimized OQC ratio, would be equivalent to about 130,000 logical qubits (13,000,000 ÷ 100).

Ledger CTO Charles Guillemet also downplayed current risks. In response to a Google report on quantum advancements, he stated that it would take “a machine with millions of stabilized and error-corrected qubits" to pose a real threat. “We're nowhere near that,” he emphasized, highlighting current technological limitations.  

Thus, compared to these expert estimates, the 50,000 logical qubits of OQC by 2034, supposedly equivalent to 5 million physical qubits, would still fall short of the 13 million physical qubits required according to Sussex. 

Therefore, despite the progress promised by companies like OQC, the quantum threat to Bitcoin seems, for now, a distant challenge, giving the ecosystem time to develop solutions such as quantum computing-resistant algorithms.