Author : Premchand Ambhore, B B Meshramr and Archana Wankhade

Cryptography is a tool that can be used to keep information confidential and to ensure its integrity and authenticity. All modern cryptographic system are based on Kirchhoff’s principle of having a publicly known algorithm and a private or secret key. Many cryptographic algorithms use complex transformations involving substitutions and permutations to transform the plain text into cipher text. However, if quantum cryptography can be made practical, the use of one pads may provide truly unbreakable cryptosystems. Cryptographic algorithms can be divided into symmetric key algorithms and public key algorithms. Symmetric key algorithms mangle the bits in a series of rounds parameterized by the key to turn the plaintext into cipher text. The main public key algorithm is RSA, public key algorithms. Commonly messages to be signed are hashed using algorithms such as MD-5 and SHA-1 and then hashes are signed rather than original messages. Including some that use a trusted third party, Diffie-Hellman, Keberos and Public-Key cryptography. Digital data transmission raises many issues in which technology interacts strongly with public policy. Some of the areas include privacy, freedom of speech and copy right. Thus we have seen the basic reasons and requirements to provide data transmission security and its importance. The data transmission security can be achieved by using combination of RSA, AES, and SHA-1 algorithms. This eliminates the threats to the data transmission security. Voice data, image and text data from Host A to Host B is sent securely.

Keywords: Security, cryptography, protocols, algorithms.

Article published in International Journal of Current Engineering and Technology, Vol.4, No.6 (Dec-2014)