World’s first quantum blueprint could crack Bitcoin’s 256-bit security in 26 days

IonQ has published what it calls the world’s first fully compiled, end-to-end blueprint for breaking 256-bit elliptic-curve signatures with a quantum computer.

The study puts a striking number on the problem. A fault-tolerant quantum machine could solve Bitcoin’s secp256k1 elliptic-curve problem in about 25.7 days, according to the estimate.

Researchers arrived at a requirement of 19,397 physical qubits for the calculation. The figure includes the hardware needed to run the algorithm with quantum error correction.

The result does not mean Bitcoin can be cracked today. IonQ has not demonstrated the attack on a working quantum computer. Instead, the paper traces the entire computation down to the operations a future machine would need to perform.

Turning Shor into hardware

Shor’s algorithm has long provided the theoretical route for breaking public-key cryptography with quantum computers. Turning that mathematics into a machine, however, creates a much larger engineering problem.

IonQ’s researchers modeled the attack against secp256k1 as an actual fault-tolerant workload. The curve has become a useful benchmark because Bitcoin relies on it and cryptographers have studied it extensively.

The resulting design uses 1,457 logical qubits and roughly 39 million Toffoli gates. Those logical resources then expand into thousands of physical qubits once error correction enters the picture.