Quantum Secure Chat System using Quantum Key Distribution and AES Encryption

In the era of quantum computing, conventional encryption methods are becoming more vulnerable to quantum attacks and more secure communication protocols are needed. This paper describes a Quantum Secure Chat System that facilitates real-time communication between two parties through Quantum Key Distribution (QKD) using the BB84 protocol and AES-GCM encryption to protect confidentiality and integrity. The system employs QKD for key distribution and mitigates eavesdropping attempts, whereby attempted interceptions alert parties that the key cannot be trusted. In conjunction, the system employs Quantum Random Number Generation (QRNG) to mitigate the risk of non-random and biased keys. From the front end perspective, the chat system has an intuitive interface built of HTML, CSS, and JavaScript for two users to communicate in encrypted format. From the back-end, it has implemented a Django REST framework for QKD, AES encryption, and message decryption. Information about eavesdropper detection, quantum keys, cipher text, and decrypted messages is displayed to the user and aids transparency in the key exchanging and data encryption/decryption process. The system was robustly developed and tested with release candidates to establish eavesdropping detection, as well as the ability to manage encryption and decryption in an efficient manner. Furthermore, it provides evidence of a strong security capability between the combinations of QKD and AES as a solution to enable real-time messaging.