The rise of quantum computing changes both the possibilities and difficulties for encryption systems. Quantum algorithms like Shor’s and Grover’s make it easier to do maths, which means they can be used to defeat classical encryption systems like RSA and symmetric encryption. Hybrid quantum-classical optimization frameworks and sophisticated techniques such as QAOA and VQE create novel opportunities to enhance the efficiency, scalability, and resilience of cryptographic systems. This study examines the enhancement of protocol design, key search, and factorization through quantum approaches, all while safeguarding against quantum adversaries. The results show how crucial it is to immediately switch to cryptographic systems that are more effective and resistant to quantum computing.