Saudi quantum computer revives fears over blockchain cryptography

Saudi Aramco, the state-controlled energy and chemicals group, said earlier this week that the neutral-atom quantum system is intended for industrial workloads such as energy modeling, optimization and materials research, not for cryptographic attacks. The machine, delivered by Pasqal and described as the company’s most powerful deployment so far, uses arrays of individually controlled atoms as qubits — the basic units of quantum information.

Pasqal CEO Loïc Henriet called the deployment a historic moment for the region, describing it as a key milestone for the Middle East’s quantum roadmap and a step toward bringing “practical quantum power” into real-world industrial settings. Saudi Arabia’s new system also places the Kingdom among a group of governments including the United States, China, the European Union, the United Kingdom, Japan, India and Canada that are funding national quantum initiatives to build research capacity and train specialist talent.

For Bitcoin and other cryptocurrencies, the announcement lands against a broader debate about so-called “Q-Day” — the point at which a fault-tolerant quantum computer could break widely used public-key schemes such as elliptic-curve cryptography. Security researchers warn that a sufficiently powerful machine could derive private keys from exposed public keys, forge digital signatures and potentially authorize unauthorized transactions from long-dormant wallets.

Experts cited in the discussions around the Aramco–Pasqal deployment stressed that today’s hardware is far from that threshold. They noted that a 200-qubit neutral-atom system remains relatively small in practical terms, with noise and limited coherence times constraining how many gate operations can be performed before errors accumulate. According to quantum researchers, running algorithms such as Shor’s at a scale that would threaten Bitcoin would require thousands of error-corrected logical qubits, which in turn implies millions of underlying physical qubits — a level no existing platform has reached.

Quantum specialists also pointed out that current machines like Aramco’s 200-qubit processor, and cutting-edge devices such as Google’s 105-qubit “Willow” chip, are being used primarily for physics simulations, chemistry, optimization and proof-of-concept algorithms, rather than for cryptanalysis. Willow recently demonstrated a “Quantum Echoes” algorithm that achieved verifiable quantum advantage on specific tasks, highlighting how fast the field is moving while still remaining far from breaking modern cryptography.

At the same time, researchers and policy makers are treating the long-term risk as serious. Academic cryptographers estimate that large-scale, fault-tolerant quantum machines could pose an “existential” threat to current digital signature schemes over a horizon of at least a decade, driving work on post-quantum algorithms and migration strategies. For Bitcoin specifically, analysts note that older addresses with long-exposed public keys and funds left unmoved for years are theoretically the most vulnerable in a future quantum era, which is why some developers are exploring quantum-resistant signature schemes and potential upgrade paths.