Image Encryption Algo - Entropy sourced from Chaos

Random numbers generated from a NL DS & used for s-box gen. Algorithms fed the s-boxes with modified DES were used for secure comm.

A modified Cipher Block Chaining (CBC) encryption scheme is proposed based on a recently reported multi-stable chaotic system with a far-reaching ergodicity space that shows high sensitivity to both states and parametric deviations. The series of numbers generated from the source sufficiently pass the various tests for randomness and pseudo-randomness as recommended by the National Institute of Standards and Technology (NIST). Substitution (S-)boxes are generated based on data from the system and are subjected to further cryptographic analyses, including nonlinearity, strict avalanche criterion, bit independence criterion, equiprobable xor-logic, and security. Specifically, the security analysis tests the robustness of the generated s-boxes on image encryption and decryption based on the modified CBC. Although each mode implements the so-called data encryption standard, using the proposed entropy source for the generation of s-boxes, initialization vectors, and permutation and resizing tables, the method holds the potential to heighten confusion and diffusion in the ciphertexts as indicated by various security tests, including correlations coefficients, histogram analysis, root-mean-square error (RMSE), entropy, and differential attacks. Performance experiments, viz. runtime and memory usage, of the proposed method is conducted to determine its applicability. Relevant algorithms are elaborated, and tables of data and graphs of simulations are presented to validate the results.