Cryptography & Quantum Computing: Why it matters and what comes next?

In today’s digital world, most of our personal, financial, and health data is stored online. This makes cybersecurity extremely important — but also more challenging. Recent cyberattacks like the one on Australia’s MediSecure show how weak security can lead to huge losses. Now, a new risk is emerging: quantum computers. These work very differently from classical computers and can break the encryption methods (like RSA and AES) that we currently use to protect online data. This paper explains how cryptography works, what types exist (symmetric and asymmetric), and why current systems may not survive in a world where quantum computers are common. It introduces powerful quantum algorithms like Shor’s and Grover’s, which can break RSA and weaken AES much faster using quantum computers than any normal computers. This shows the power of quantum computers. These developments have pushed scientists to create new encryption systems called Post-Quantum Cryptography (PQC), which are built to resist quantum attacks but still run on regular devices. The paper also explores how quantum computing is evolving — from early research in the 1980s to real working processors today — and how countries and companies are investing in this technology. It suggests that in the future, people may access quantum computers over the cloud, rather than owning them. Finally, this research shows that the rise of quantum computing is both a threat and an opportunity. It challenges us to update our security systems, but it also opens the door for new startups and careers in quantum-safe cybersecurity.