International Journal of Advanced Computing, ISSN: 2051-0845, Vol., Issue. 1 © RECENT SCIENCE PUBLICATIONS ARCHIVES | May 2015|$25.00 | 27704366| *This article is authorized for use only by Recent Science Journal Authors, Subscribers and Partnering Institutions* Novel Authentication Protocol Using Multi Cryptographic Hashfunctions and Steganography B. Madhuravani Department of CSE, MLR Institute of Technology, Hyderabad Email:madhuravani.peddi@gmail.com Dr. D. S. R. Murthy Professor & Head Dept of CSE Geethanjali College of Engg. and Tech, Hyderabad Dr. P. Bhaskara Reddy Director MLR Institute of Technology, Hyderabad Email:director@mlrinstitutions.ac.in ABSTRACT Authentication plays a vital role in securing communication network between two parties. The communication network needs to be protected from unauthorized users. Security can be provided by using two popular methods cryptography and steganography. Cryptography provides secure communication from adversaries by scrambling the information, where as the steganography hides the information in another medium which cannot be detected by normal human eye. This paper introduces a new technique which provides high security to the communication network by using multiple hash functions for integrity and embeds the information in an image file using steganography to misguide third party, by which we provide high security for the communication network between two parties. Keywords- Cryptography, Steganography, Human Visual System (HVS), Least Signficat Bit (LSB) 1. INTRODUCTION As the internet changed our day to day life, which became a media for every communication with internet business and online services. To do anything people are using internet like to share their personal and private information in several social networks. People are performing several online transactions like buying things online, funds transfer, ticket booking etc. Security and privacy becomes a major concern in these transactions. An adversary from other end attempts to discover the private information, trying to actively corrupt the important or confidential data, eavesdropping or down the services to make the system unavailable to intended users. Security has become a major concern in digital communication. Hence to establish secure transmission between two entities, two techniques were in use: One is Cryptography which provides security services like protecting confidential information, guard our data from re arranging and helps in exchanging the keys between two parties securely. But adversaries can observe the things that are happening between entities. Whereas steganography from other end took a forward step from cryptography by hiding secret information in other object which can misguide the hacker. If the embedded data or file size is large this may create a suspicious situation for a hacker and also becomes very dangerous when it is on the wrong hands like terrorists and criminals. Users are using either cryptography or steganography for secure communication but the fact is neither cryptography nor steganography gives a complete solution to establish a secure digital communication over the internet. Hence, in this paper we propose to provide security in multiple layers by combining cryptography and steganography together to provide and enhance security services. The remaining paper is organized as follows: In section 2, we briefly discuss about different cryptographic hash functions for message authentication. In section 3, we outline steganography techniques. In section 4, we present our proposed Authentication protocol using different hash functions and steganography. Section 5, presents our simulated results. The last section concludes the paper. 2. CRYPTOGRAPHIC HASH FUNCTIONS A hash function maps a variable-length input into a fixed- length output. The hash function output will be treated as a fingerprint of the input data [1] which maps the variable length input to a fixed length output. Cryptographic hash functions play a vital role in, message integrity, user authentication, digital signatures, password protection and generating pseudo random numbers. Authentication protocols such as Kerberos uses hash function. Kerberos offers authentication, eavesdropping prevention, and integrity of data in client-server architecture. Hash functions provide secure communication protocols such as Internet Protocol Security (IPSec), Secure Socket Layer (SSL). The handshaking protocol in SSL uses a hash function to create a message authentication code. To ensure the integrity of e-mail messages in Pretty Good Privacy (PGP) and Secure/Multipurpose Internet Mail Extensions (S/MIME) hash functions are used widely. Mathematically a hash functions is defined as MD = H F (M), where HF is a hash function hold the following properties [2]. a. One way function- it is possible to calculate MD from M but it is impossible to calculate M from MD. b. Difficult to find messages M1 and M2 which generates same message digest i.e H F (M1)≠ H F (M2) the best known algorithms to generate message digest are MD-2, MD-4, MD-5, SHA-0, SHA-1, SHA-2 and SHA-3.