Quantum computers capable of cracking bitcoin encryption will be “feasible” with “future progress”, the researchers say.

The researchers estimated how big a quantum computer would need to be to break bitcoin network encryption as a test to see how big a quantum computer would need to be in the future to perform other tasks.

“Most of the existing work in this area focuses on one particular hardware platform, superconducting devices, like those that IBM and Google are working towards,” said Mark Webber, then of the University of Sussex, who led the study. research.

“Different hardware platforms will vary widely in key hardware specifications, such as rate of operations and quality of control over qubits.”

Quantum computers work by replacing traditional bits – the “1s” and “0s” used to encode digital information – with quantum bits, or qubits.

These can function as both a ‘1’ and a ‘0’ at the same time by existing in a state of superposition, which means that each new qubit added to the computer increases its power exponentially rather than linearly. .

Many of the promises made by quantum computing will require an error-correcting quantum computer. This allows longer algorithms to run by compensating for inherent errors inside the computer, at the cost of more physical qubits needed.

“To speed up the execution of the quantum algorithm, we can perform more operations in parallel by adding more physical qubits. We introduce additional qubits as needed to achieve the desired runtime, which essentially depends on the rate of operations at the physical hardware level.

Most quantum computers are limited because only qubits next to each other can interact. In other designs, qubits can be physically moved to interact with others.

Quantum computers are better at cracking encryption than conventional computers. Most secure communications use RSA (Rivest–Shamir–Adleman) encryption, first described in 1977.

The security of the system relies on the practical difficulty of factoring two large prime numbers, which are the basis of the public key. A message “locked” by such a key can only be decoded if the receiver knows the prime numbers.

Bitcoin, on the other hand, uses the elliptic curve digital signature algorithm, but researchers suggest that both methods will be vulnerable to an attack in the future.

“Edge quantum computers today only have 50 to 100 qubits,” Webber said. “Our estimated need of 30 [million] at 300 million physical qubits suggests that Bitcoin should be considered immune to quantum attack for now, but devices of this size are generally considered feasible, and future progress could lower the requirements even further.

Bitcoin may be able to “hard-fork” to a secure quantum encryption technique, but increased memory requirements could lead to network scaling issues.

“The Impact of Hardware Specifications on Reaching Quantum Advantage in the Fault Tolerant Regime” was published in AVS Quantum Sciences.