Integrasi Algoritma RSA dan Teknologi Kriptografi Kuantum dalam Keamanan Aplikasi Web Chatting

Abstract

Abstract
In today’s digital era, ensuring the security of data and messages is crucial, especially on web-based chatting platforms that are widely used for personal and professional communication. Sensitive information transmitted over the internet remains vulnerable to interception and manipulation by unauthorized parties. This study implements a hybrid security scheme that integrates the RSA public-key algorithm with simulated Quantum Key Distribution (QKD) using the BB84 protocol to secure key exchange and end-to-end encryption in a web chatting application. RSA-OAEP is used to wrap AES-256 session keys for each chat, while the BB84 module supplies a quantum-derived pad and QBER-based security signal to detect potential eavesdropping on the key exchange process. Private RSA keys are stored entirely on the client side, and all messages are encrypted using AES-GCM in the browser so that the server never accesses plaintext content. The developed system supports user registration, contact management, chat initialization, secure key provisioning, encrypted message exchange, and automatic key rotation when QBER exceeds a defined threshold. Security evaluation, including brute-force and factorization analysis of RSA key sizes, QKD simulation experiments, and black box testing of the application workflow, shows that the prototype effectively maintains message confidentiality, detects simulated interference on the key channel, and performs encryption–decryption accurately with acceptable latency for practical use.