16-07-2013, 04:35 PM
TEXT FILE HIDING IN AUDIO FILE USING LOW BIT ENCODING STEGANOGRAPHY
TEXT FILE HIDING .doc (Size: 3.34 MB / Downloads: 83)
INTRODUCTION
AIM OF THE PROJECT:
We are of the belief that the easiest way to keep something from prying eyes is to place it right in front of the person looking for it and make it look as innocuous as possible.
Everyone has a taste for a certain kind of music. Hence, it is more than likely that the person will have that kind of music on the storage device of his computer. Also, it is quite common case where people share and transfer different music files to one another. If one were able to hide the message can be. Also, transfer of this message can be done quite conveniently without raising any eyebrows.
Our aim is to come up with a technique of hiding the message in the audio file in such a way, that there would be no perceivable changes in the audio file after the message insertion. At the same time, if the message that is to be hidden were encrypted, the level of security would be raised to quite a satisfactory level. Now, even if the hidden message were to be discovered the person trying to get the message would only be able to lay his hands on the encrypted message with no way of being able to decrypt it.
STEGANOGRAPHY IN AUDIO:
Data hiding in audio signals is especially challenging, because the Human Auditory System (HAS) operates over a wide dynamic range. The HAS perceives over a range of power greater than one billion to one and a range of frequencies greater than thousand to one. Sensitivity to additive random noise is also acute.
The perturbations in a sound file can be detected as low as one part in ten million which is 80dB below ambient level. However there are some ‘holes’ available. While the has a large dynamic range, it has a fairly small differential range. As a result, loud sounds tend to mask out the quieter sounds.
Additionally, the HAS is unable to perceive absolute phase, only relative phase. Finally there are some environmental distortions so common as to be ignored by the listener in most cases.
LOW-BIT ENCODING:
Low-bit encoding is the one of the simplest way to embed data into other data structures. By replacing the least significant bit of each sampling point by a coded binary string, we can encode a large amount of data in an audio signal.
Ideally, the channel capacity is 1 kb per second (kbps) per 1 kilohertz(kHz), e.g., in a noiseless channel, the bit rate will be 8 kbps in an 8 kHz sampled sequence and 44 kbps in a 44kHz sampled sequence. In return for this large channel capacity, audible noise is introduced. The impact of this noise is a direct function of the content of the host signal, e.g., crowd noise during a live sports event would mask low-bit encoding noise that would be audible in a string quartet performance.
EXISTING SYSTEM:
Nowadays, several methods are used for communicating secret messages for defense purposes or in order to ensure the privacy of communication between two parties. So we go for hiding information in ways that prevent its detection.
Some of the methods used for privacy communication are the use of invisible links, covert channels are some of existing systems that are used to convey the messages.
PROPOSED SYSTEM:
The proposed system uses Audio file as a carrier medium which add another step in security. The objective of the newly proposed system is to create a system that makes it very difficult for an opponent to detect the existence of a secret message by encoding it in the carrier medium as a function of some secret key and that remains as the advantage of this system
SOFTWARE REQUIREMENTS SPECIFICATION
Software Requirements Specification (SRS) is the starting point of the software development activity. Little importance was given to this phases in the early days of software development. The emphasis was first on coding and then shifted to design.
As systems grew more complex, it become evident that the goal of the entire system cannot be easily comprehended. Hence need for the requirements analysis phase arose. Now, for large software systems, requirements analysis is perhaps the most difficult activity and also the most error prone.
Some of the difficulty is due to the scope of this phase. The software project is imitated by the client needs. In the beginning these needs are in the minds of various people in the client organization. The requirement analyst has to identify the requirements by tacking to these people and understanding there needs. In situations where the software is to automated a currently manuals process, most of the needs can be understood by observing the current practice.
The SRS is a means of translating the ideas in the minds of the clients (the output) into formal document (the output of the requirements phase). Thus the output of the phase is a set of formally specified requirements, which hopefully are complete and consistent, while the input has none of these properties.
CONCLUSION
Steganography transmits secrets through apparently innocuous covers in an effort to conceal the existence of a secret. Audio file Steganography and its derivatives are growing in use and application. In areas where cryptography and strong encryption are being outlawed, citizens are looking at Steganography to circumvent such policies and pass messages covertly.
Although the algorithm presented is a simple one and not without its drawbacks, it represents a significant improvement over simplistic steganographic algorithms that do not use keys. By using this algorithm, two parties can be communicated with a fairly high level of confidence about the communication not being detected.
In designing the “Steganography” utmost care was taken to meet user requirements as much as possible. The analysis and design phase was reviewed. Care was taken strictly to follow the software engineering concepts. And principles so as to maintain good quality in the developed system as per the user requirements.