QSMS: A Quantum-Secured Mail System for Post-Quantum Resilient Email Communication

As quantum computing continues to evolve and threaten traditional encryption methods, the need for secure email communication has never been higher. In this paper an unbreakable encryption framework: Quantum-Secured Mail System (QSMS), based on Quantum Key Distribution (QKD) using the No-Cloning Theorem is proposed. In contrast to traditional cryptography methods that are based on computational hardness, QKD provides secure key distribution using quantum mechanics, thus causing any eavesdropper action to be detectable in real time due to disturbance in the quantum system. Due to the No-Cloning Theorem, our solution limits the unauthorized replication of encryption keys, hence giving a fundamental improvement over security based on RSA. We propose QSMS, which is based on a hybrid cryptographic paradigm in which the QKD provides the security of the exchanged key and AES provides fast and efficient email encryption. The approach offers quantum-resilient security while maintaining compatibility with existing email systems, which is necessary for making the systems practically usable. “Real-time eavesdropping detection is also offered, with dynamic response to interception attempts regenerating encryption keys.” The QA-ree runs the performance analysis of the system to show that it can ensure a minimal Quantum Bit Error Rate(QBER) of only 1.52% which ensures the reliability of the key distribution with minimal error correction. The decryption and encryption times are still computationally efficient, thus allowing QKD-powered email security suitable for real-time transmission. By combining quantum cryptography with classical encryption, this approach enables a scalable and future-proof shield against both classical and quantum cyber threats.