How Many Qubits Does a Quantum Computer Need?

The number of qubits required for a useful quantum computer remains a pressing question, with answers often provided without clear justification. Recent announcements have touted systems with hundreds of qubits, but the actual number needed is still uncertain. Experts from Firgun Ventures and Relational Intelligence Limited have weighed in on the issue, emphasizing the need for a more nuanced understanding of quantum computing requirements. A useful quantum computer will likely require a significant number of high-quality qubits, rather than simply a large quantity¹. As companies like Intel continue to advance quantum developments, the timeline for cryptographic migration is narrowing, making planning for post-quantum cryptography increasingly urgent. This raises the stakes for organizations to assess their cryptographic vulnerabilities and develop strategies for migration to quantum-resistant systems, underscoring the need for informed decision-making in the face of rapid quantum computing advancements.