M. Ramkumar, Symmetric Cryptographic Protocols, Springer, August 2014.
H.T Sencar, M. Ramkumar and A.N. Akansu, Data Hiding Fundamentals and Applications: Content Security in Digital Multimedia, Elsevier Academic Press, July 2004.
PhD's thesis: Data Hiding in Multimedia : Theory and Applications. pdf October 1999.
Master's thesis: Some New Methods for Improved Fractal Image Compression. pdf December 1996.