Dec 01, 2015
1.1 INTRODUCTION:-Information security(sometimes shortened to InfoSec) is the practice of defendinginformationfrom unauthorized access, use, disclosure, disruption, modification, perusal, inspection, recording or destruction. It is a general term that can be used regardless of the form the data may take (electronic, physical, etc...)Below are the fundamentals when dealing with information security:IT Security= Sometimes referred to ascomputer security, Information Technology Security is information security when applied to technology (most often some form of computer system).Information Assurance= The act of ensuring that data is not lost when critical issues arise. These issues include but are not limited to; natural disasters, computer/server malfunction, physical theft, or any other instance wheredatahas the potential of being lost.Governments,military,corporations,financial institutions,hospitals, and privatebusinessesamass a great deal of confidential information about their employees, customers, products, research and financial status. Most of this information is now collected, processed and stored on electroniccomputersand transmitted acrossnetworksto other computers.Should confidential information about a business' customers or finances or new product line fall into the hands of a competitor, such a breach of security could lead to negative consequences. Protecting confidential information is a business requirement, and in many cases also an ethical and legal requirement.For the individual, information security has a significant effect onprivacy, which is viewed very differently in differentcultures.The field of information security has grown and evolved significantly in recent years. In the project we study about and apply algorithms related to an important part of information security, steganography using both image and text as a cover medium.
1.2 NECESSITY:-One of the reasons that intruders can be successful is the most of the information they acquire from a system is in a form that they can read and comprehend. Intruders may reveal the information to others, modify it to misrepresent an individual or organization, or use it to launch an attack. One solution to this problem is, through the use of steganography. Steganography is a technique of hiding information in digital media. In contrast to cryptography, it is not to keep others from knowing the hidden information but it is to keep others from thinking that no information even exists. Steganography became more important as more people joined the cyberspace revolution. On a more general sense, steganography is the art of concealing information in ways that prevents even the detection of hidden messages. Steganography includes an array of secret communication methods that keeps the message from being seen or discovered. Due to advances in computing, networking and internetworking most of information is kept electronically. Consequently, the security of information has become a fundamental issue. Besides cryptography, steganography can be employed to secure information in the next level. In steganography, the message or encrypted message is embedded in a digital host before passing it through the network, thus the existence of the message is unknown. Besides hiding data for confidentiality, this approach of information hiding can be extended to authentication i.e., copyright protection for digital media: audio, video and images. The growing possibilities of modern communications need the special means of security especially on computer network. The network security is becoming more important as the number of data being exchanged on the internet increases. Therefore, the confidentiality and data integrity are requires to protect against unauthorized access and use. This has resulted in an explosive growth of the field of information hiding. Information hiding is an emerging research area, which encompasses applications such as copyright protection for digital media, watermarking, fingerprinting, and steganography. In watermarking applications, the message contains information such as owner identification and a digital time stamp, which usually applied for copyright protection. Fingerprint, the owner of the data set embeds a serial number that uniquely identifies the user of the data set. This adds to copyright information to makes it possible to trace any unauthorized used of the data set back to the user. Steganography hide the secrete message within the host data set and makes its presence imperceptible and is to be reliably communicated to a receiver. The host data set is purposely corrupted, but in a covert way, designed to be invisible to an information analysis.
1.3 OBJECTIVES:-This project is developed for hiding information i.e, text in any image or text file. The scope of the project is implementation of steganography tools for hiding information using algorithms such as the LSB algorithm (for the cover medium image) and the White Space algorithm (for the cover medium text). Thus the main objectives of our project, like most steganographic tool, are: To communicate reliably a secret message from a source to a destination. To hide the presence of the secret message from the third party. To design practical secured stego methods.
1.3.1 METHODOLOGIES:-The project presents a user-friendly and simple but efficient application which effectively hides a text message in an image file or text file selected by the user. If the user wants to use an image as a cover medium, the message is hidden using a steganographic algorithm, LSB. If , on the other hand, text is selected as the cover medium, the White Space algorithm is used.In case of the LSB, after using the encrypt menu, we achieve an image that looks apparently identical to the original image we selected for our application. To extract the information (or, the hidden text on our case) we select the decrypt option and on running the decrypt function the application separates the message from the image thus fulfilling the basic project objective. This technique is chosen, because this system includes not only imperceptibility but also un-detectability by any steganalysis tool.While, in case of the White Space algorithm, the message is encrypted by using the white spaces in the messages , that depend on whether the particular bit in the message is a 0 or a 1.Later , during decryption, the white spaces are decoded to give us back the bits to be reconstructed into the respective characters using the ASCII values, thus giving us back the original text.An authentication mechanism in each of the particular encrypted file (be it image or text) has been introduced in the form of a unique authentication code randomly generated by the system during encryption. This authentication ID enables one to access the file and thus adds security on an individual file basis.
Information hiding (or data hiding) is a general term encompassing a wide range of problems beyond that of embedding messages in content. The term hiding here can refer to either making the information imperceptible (as in watermarking) or keeping the existence of the information secret. The inventor of the word steganography is Trithemius, the author of the early publications on cryptography: Polygraphia and Steganographia. The technical term itself is derived from the Greek words steganos, which means covered, and graphia, which means writing. Steganography is the art of concealed communication. The very existence of a message is secret.Steganography is the practice of hiding private or sensitive information within something that appears to be nothing out to the usual. Steganography is often confused with cryptology because the two are similar in the way that they both are used to protect important information. The difference between two is that steganography involves hiding information so it appears that no information is hidden at all. If a person or persons views the object that the information is hidden inside of he or she will have no idea that there is any hidden information, therefore the person will not attempt to decrypt the information.What steganography essentially does is exploit human perception, human senses are not trained to look for files that have information inside of them, although this software is available that can do what is called Steganography. The most common use of steganography is to hide a file inside another file. Two different applications of steganography are:The first is what we call classical steganography, and its aim is that of transmitting a message by means of another innocent or casual-looking mediumThe second is invisible digital watermarking, which purpose is to assess the ownership or integrityOf some pieces of information, named after the watermarks we are used to see on bills or legal documents for the same purpose. It can be used also to provide additional information on a message inside a message itself.Since we are using both image and text file for hiding text and using different algorithms for both subparts of our application, here we attempt to give a brief insight into the functioning of both,, namely LSB and White Space algorithm.
1.4.1 STEGANOGRAPHIC SYSTEM:-
FIG 1.4.1: Steganographic System The terms used are as follows :
fE : steganographic function "embedding" fE-1 : steganographic function "extracting" cover: cover data in which embedding will be hidden emb:message to be hidden key:parameter of fE and fE-1 stego: cover data with the hidden message Note : cover* are the cover data in which emb was hidden and has been extracted emb* is the hidden text that has been extracted.
The following formula provides a very generic description of the pieces of the steganographi