In in this talk we explore the potential ramifications of quantum computing in the field of cybersecurity We'll delve into two critical aspects: the application of quantum machine learning algorithms for defence and the impact of quantum attacks on cryptography and post-quantum cryptography for offence. We'll present insights on the theoretical advantages of quantum algorithms, improvements in factoring large numbers, and the impacts of post-quantum crypto attacks. While the hype around quantum technologies is growing, the estimates in the resources needed to run a quantum algorithm and the current number of qubits pose caution in the enthusiasm. The limitations in terms of available qubits, error rates, and scalability are critical factors that need to be considered when assessing the real-world applicability of quantum computing.