Abstract: We live in a world where billions of devices are connected to the internet from smart home gadgets to hospital monitors to factory machines. All of these devices rely on security systems built with traditional encryption (methods for scrambling data so only the right person can read it). These encryption methods have protected us well for decades. But a new type of computer, called a quantum computer, is on the horizon and it could break most of today's encryption in a matter of seconds. That's a very serious problem.
This review paper brings together findings from several research studies to explain the problem clearly and to explore the solutions being developed. We look at how quantum computers threaten our current systems. what new types of encryption(called post-quantum cryptography, or PQC) are being created to replace them, and how blockchain technology the same technology behind cryptocurrencies can be made quantum-safe. We also explore how a technique called Quantum Key Distribution (QKD) can share secret keys in a way that is guaranteed to be safe by the laws of physics. Finally, we look at how Artificial Intelligence (AI) can both help protect systems and, in the wrong hands, help attack them. The paper ends with an honest look at what still needs to be solved and where researchers should focus their efforts next.

Keywords: Quantum Computers, Post-Quantum Cryptography (PQC),Blockchain Security, Internet of Things (IoT), Quantum Key Distribution (QKD), 6G Networks, Artificial Intelligence Security

Downloads: | DOI: 10.17148/IJIREEICE.2026.14382