Sizing up the quantum threat to cyber security: Making sense of quantum computing headlines

Quantum computing is predicted to pose a critical threat to traditional public-key cryptography and weak forms of symmetric cryptography if a massive-scale ‘cryptographically relevant’ quantum computer (CRQC) is successfully developed at some future point. Sensationalised headlines reflect fluctuating hype over these emerging technologies and present a distinct challenge for cyber security professionals outside the quantum computing research and development (R&D) space to rationalise. This paper offers a practical scaffold for making sense of headlines about quantum computing progress and its potential significance for cyber security. Context is offered on the wide range of quantum computers being developed and key challenges they have yet to surmount, the ambiguous terminology and uncertain milestones benchmarking quantum computing progress to date, key assumptions that underpin the spectre of a so-called ‘Q-day’ cyber security crisis scenario, and the wide distribution of expert opinion about the quantum computing future. Cyber security professionals are counselled to exercise a healthy caution in their read of quantum computing headlines, but to pursue prompt migration towards quantum-safe standards as part of a broader focus on system-wide cyber resilience. This article is also included in The Business & Management Collection which can be accessed at https://hstalks.com/business/.