Abstract:
The rapid growth of quantum computing poses a significant threat to traditional cryptographic
systems, such as RSA and ECC, which are widely used to protect sensitive information in
various sectors, including finance, healthcare, and government. These methods rely on
mathematical problems that quantum computers could solve far more quickly, raising concerns
that encrypted data may soon become vulnerable. At the same time, traditional steganography
is becoming easier to detect due to the improvement of analysis tools, making it harder to hide
secret communication effectively. This project addresses these challenges by combining post-
quantum cryptography with steganography to enhance data security and secrecy.
To solve this problem, the project designs and implements a Post-Quantum Cryptographic
Steganography (PQCS) system. It utilises Kyber512, a lattice-based encryption method
resistant to quantum attacks, in conjunction with AES256 encryption for enhanced protection.
The encrypted message is then hidden inside a PNG image using Least Significant Bit (LSB)
steganography, allowing covert communication while keeping the image visually unchanged.
The system also includes basic logging to monitor key events during encryption and
embedding, and follows a modular, procedural design for simplicity and cross-platform
compatibility.
Initial tests indicate that the prototype can successfully encrypt, embed, and recover secret
messages without altering the carrier images visibly. The Peak Signal-to-Noise Ratio (PSNR)
was measured at 76.40 dB, and the Structural Similarity Index (SSIM) was 1.0000, indicating
excellent visual fidelity between the original and stego images. Additionally, both the encoding
and decoding processes were completed in under 30 seconds, confirming the system’s
efficiency. These results demonstrate that merging post-quantum cryptography with
steganography is a promising approach for building secure communication systems that can
withstand emerging quantum threats.
