Multi-level Post Quantum Encryption for Images with Quantum Fourier Transform

The rise of quantum computing poses an imminent threat to traditional cryptographic algorithms such as Advanced Encryption Standard (AES) and Rivest, Shamir, Adleman (RSA), necessitating innovative solutions to ensure data security in the post-quantum era. This paper introduces a novel multi-level image encryption system that combines post-quantum and conventional techniques to address this challenge. By leveraging the Quantum Fourier Transform (QFT) to decompose images, encrypting low-frequency components with Advanced Encryption Standard (AES), and securing AES keys with the quantum-resistant Learning with Errors (LWE) method, this approach offers robust protection against classical and quantum attacks. Empirical evaluations using metrics such as Peak Signal-to-Noise Ratio (PSNR), Structural Similarity Index (SSIM), entropy, and correlation coefficients demonstrate the system's ability to maintain image quality while delivering exceptional security. Scalable and effective, this framework is well-suited for safeguarding critical applications in fields such as medicine, defense, and finance.