Facilitating and securing offline e-medicine service through image steganography

Design of cryptographically secure AES like S-Box using second-order reversible cellular automata for wireless body area network applications

In biomedical, data security is the most expensive resource for wireless body area network applications. Cryptographic algorithms are used in order to protect the information against unauthorised access. Advanced encryption standard (AES) cryptographic algorithm plays a vital role in telemedicine applications. The authors propose a novel approach for design of substitution bytes (S-Box) using second-order reversible one-dimensional cellular automata (RCA²) as a replacement to the classical look-up-table (LUT) based S-Box used in AES algorithm. The performance of proposed RCA² based S-Box and conventional LUT based S-Box is evaluated in terms of security using the cryptographic properties such as the nonlinearity, correlation immunity bias, strict avalanche criteria and entropy. Moreover, it is also shown that RCA² based S-Boxes are dynamic in nature, invertible and provide high level of security. Further, it is also found that the RCA² based S-Box have comparatively better performance than that of conventional LUT based S-Box.