Information Technology Journal1812-56381812-5646Asian Network for Scientific Information10.3923/itj.2005.204.221RabahKefa 3200543In this study we present the techniques that are useful in securing the data against tamper in between communicating parties by the man in the middle. This involves the use and implementation of message digest (or hashing), message authentication and digital signature schemes. A hash function can provide message authentication in a most satisfying manner when combined with digital signature algorithm, which does have a key. Digital signatures currently provide Internet applications with data authentication and non-repudiation services and is set to continue playing an important role in future as Internet services continues to grow. Typical digital signature schemes, however, have some performance overhead, which, while acceptable for the periodic setup of communication sessions, is often too large on a message-by-message basis. Thus, the need today is to focus on the message authentication based on shared secrete-key, which is ideally integrated into the hash function in some manner and thats the subject of this study.]]>Comer, D.E.,19992nd Edn.,Rivest, R.,1992Gavin, J. and K. McCloghrie,1993Bellare, M., K. Joe and R. Phillip,19901990pp: 341-358pp: 341-358Damgard, I.B.,19901990pp: 416-427pp: 416-427Merkle, R.,19901990pp: 428-446pp: 428-446Gene, T.,19921992pp: 20552059Kaliski, B. and M. Robshaw,1995Canetti, R.B. and H. Kaawczyk,19981998pp: 419428Bellare, M., G. Roch and R. Philip,19951995Kelsey, J., B. Schneier, D. Wagner and C. Hall,1998pp: 168-188pp: 168-188Blum, M. and S. Micali,198413850864Rabah, K.,20043106132Rivest, R., A. Shamir and L.M. Adleman,19831983International Organization for Standardization,19981998Dobbertin, H., A. Bosselaers and B. Preneel,19961996pp: 7182Menezes, A.J., P.C. van Oorschot and S.A. Vanstone,1997Christoffersson, P., S.A. Ekahll, V. Fak, S. Herda, P. Mattila, W. Price and H.O. Widman,1998Rivest, R.L., A. Shamir and L. Adleman,197821120126Rabin, M.O.,1979Preneel, B.,20032003Diffie, W. and M.E. Hellman,196622644654Elgamal, T.,198531469472FIPS 186,1993Schnorr, C.,19914161174Rueppel, N.K.,199676181Rabah, K.,20055604633Rivest, R.L.,19911991pp: 625-626pp: 625-626Heileman, G.L.,1996Housley, R., W. Ford, W. Polk and D. Solo,19991999