Information Security using Cryptography and Steganography Neetha Francis, Asst. Professor, Dept. of Computer Science, Pazhassi Raja College, Pulpally Abstract- In today’s information technology era, the internet is an essential part for communication and information sharing. Providing confidential information and establishing concealed association has been a great interest since long time ago. The security of information passed over an open channel has become a fundamental issue and therefore, the confidentiality and data integrity are required to protect against unauthorized access and use. Cryptography and steganography are the two popular methods available to provide security. Cryptography scrambles a message so it cannot be understood and generates cipher text. Steganography word is derived from Greek, literally means “Covered Writing”. Steganography is the art of hiding the existence of data in another transmission medium to achieve secret communication. It does not replace cryptography but rather boosts the security using its obscurity features. It includes vast ways of secret communications methods that conceal the message’s existence. In Cryptography, the meaning of data has been changed. So, it makes intention to the hacker to hack or destroy the data. In our proposed paper, we implement a method by integrating both Cryptography and Steganography for information security. It not only changes the meaning of data but also hides the presence of data from the hackers. In order to secure the transmission of data, Steganography has to be implemented that allow information to be sent in a secure form in such a way that the only person able to retrieve this information is intended recipient. Keywords: - Cryptography, Steganography, LSB, Data hiding, Stego-image, Diffie-Hellman Key Exchange I INTRODUCTION Cryptography and Steganography are well known and widely used techniques that manipulate information in order to cipher or hide their existence respectively. Steganography is the art and science of communicating in a way which hides the existence of the communication. Cryptography scrambles a message so it cannot be understood; Steganography hides the message so it cannot be seen. Even though both methods provide security, a study is made to combine both cryptography and steganography methods into one system for better confidentiality and security. Cryptography systems can be broadly classified into symmetric-key systems that use a single key that both the sender and the receiver have, and public-key systems that use two keys, a public key known to everyone and a private key that only the recipient of messages uses. In Cryptography, a cipher message for instance, might arouse suspicion on the part of the recipient while an invisible message created with steganographic methods will not. However, steganography and cryptography differ in the way they are evaluated: steganography fails when the ”enemy” is able to access the content of the cipher message, while cryptography fails when the ”enemy” detects that there is a secret message present in the steganographic medium. The disciplines that study techniques for deciphering cipher messages and detecting hidden messages are called cryptanalysis and steganalysis. The former denotes the set of methods for obtaining the meaning of encrypted information, while the latter is the art of discovering covert messages. The aim of this paper is to describe a method for integrating cryptography and steganography through some media such as image, audio, video, etc. Cryptography and Steganography are often interrelated and share the common goals and services of protecting the confidentiality, integrity and availability of information; which are some of the most important fields in computer security. Cryptography and steganography are methods of transferring private information and data through open network communication, so only the receiver who has the secret key can read the secret messages which might be documents, images or other forms of data. Cryptography and steganography also contribute to Computer Science, particularly, in the techniques used in computer and network security for access control and information confidentiality. They are also used in many applications encountered in everyday life. Despite the differences between Cryptography and Steganography systems the requests for them have increased recently for the fast development of the Internet publicly. II HISTORY Cryptography has followed man through many stages of evolution. Cryptography can be found as far back as 1900 B.C. in ancient Egyptian scribe using non-standard hieroglyphics in an inscription. From 500 – 600 B.C. Hebrew scribes used ATBASH, a reversed alphabet simple solution cipher. From 50 - 60 B.C. Julius Caesar used a simple substitution with the normal alphabet in government communications. Cryptography continued through history with many variations. Today cryptography has reached a new level, quantum cryptography. Quantum cryptography International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 Published by, www.ijert.org NSRCL-2015 Conference Proceedings Volume 3, Issue 28 Special Issue - 2015