InvisiCrypt: A Dual-Layer Secure Communication Framework Integrating AES-256 Encryption with Complexity-Adaptive LSB Steganography

This paper presented InvisiCrypt, a dual-layer secure communication framework unifying AES-256 CBC cryptography with a complexity-adaptive LSB steganographic pipeline. Evaluation on a 200-image benchmark confirmed PSNR of 52.83 dB and SSIM of 0.9991 at 52% embedding capacity, outperforming five state-of-the-art hybrid schemes. Steganalysis detection rates of 3.8–6.1% across histogram, chi-square, and RS methods confirm that the embedded payload is statistically indistinguishable from natural image noise. The primary limitation — vulnerability to JPEG quantisation — motivates extending embedding to the DCT frequency domain for lossless-equivalent operation on JPEG carriers. Incorporating public-key encapsulation for key distribution and evaluating resistance against deep convolutional steganalysis networks are further planned enhancements. InvisiCrypt demonstrates that strong cryptography and perceptually adaptive steganography are mutually reinforcing: encryption randomises the payload into noise-like ciphertext, while adaptive embedding distributes that noise in visually complex regions where it is imperceptible — a synergy that is the core architectural principle of the framework.

[1]  F. A. P. Petitcolas, R. J. Anderson, and M. G. Kuhn, “Information hiding — a survey,” Proc. IEEE, vol. 87, no. 7, pp. 1062–1078, Jul. 1999. [2]  N. Provos and P. Honeyman, “Hide and seek: An introduction to steganography,” IEEE Security & Privacy, vol. 1, no. 3, pp. 32–44, May–Jun. 2003. [3]  G. J. Simmons, “The prisoners’ problem and the subliminal channel,” in Proc. CRYPTO 1983, LNCS, vol. 196, pp. 51–67, Springer, 1984. [4]  C.-K. Chan and L. M. Cheng, “Hiding data in images by simple LSB substitution,” Pattern Recognition, vol. 37, no. 3, pp. 469–474, Mar. 2004. [5]  D.-C. Wu and W.-H. Tsai, “A steganographic method for images by pixel-value differencing,” Pattern Recognition Letters, vol. 24, no. 9–10, pp. 1613–1626, Jun. 2003. [6]  National Institute of Standards and Technology, “Advanced Encryption Standard (AES),” FIPS Pub. 197, Nov. 2001. [Online]. Available: https://doi.org/10.6028/NIST.FIPS.197 [7]  B. Schneier, Applied Cryptography, 2nd ed. New York, NY: Wiley, 1996. [8]  S. Bhattacharyya, I. Banerjee, and G. Sanyal, “A novel approach of data hiding using pixel mapping method,” Int. J. Comput. Sci. Inf. Security, vol. 8, no. 2, pp. 146–154, 2010. [9]  H. Al-Dmour and A. Al-Ani, “A steganography embedding method based on edge identification and XOR coding,” Expert Syst. Appl., vol. 46, pp. 293–306, Mar. 2016. [10] P. Thiyagarajan, G. Aghila, and V. P. Venkatesan, “Reversible dynamic secure steganography for medical image using genetic algorithm,” IET Image Process., vol. 7, no. 4, pp. 342–351, Jun. 2013. [11] B. Xu, J. Wang, T. Chen, and S. Pan, “Structural design of convolutional neural networks for steganalysis,” IEEE Signal Process. Lett., vol. 23, no. 5, pp. 708–712, May 2016.