Steganalysis from and Operating Systems and Architecture Standpoint

Steganalysis from and Operating Systems and Architecture Standpoint

Introduction

The goal of steganography is to avoid drawing suspicion to the transmission of a hidden message. If suspicion is raised, then this goal is defeated. Discovering and rendering useless such covert messages is a new art form known as steganalysis. In this paper, we provide an overview of some characteristics in information hiding methods that direct the steganalyst to the existence of a hidden message and identify where to look for hidden Information.

Steganography literally means, "covered writing" and encompasses methods of transmitting secret messages through innocuous cover carriers in such a manner that the existence of the embedded messages is undetectable. Carriers of such messages may resemble innocent images, audio, video, text, or any other digitally represented code or transmission. The hidden message may be plaintext, ciphertext, or anything that can be represented as a bit stream. Commercial use of steganographic techniques has evolved into digital watermarking. Watermarking does not necessarily conceal the knowledge of the hidden information other than from the human senses.

Theoretical Overview of Steganalysis and Data Recovery

Steganalysis Tools vs. Data Recovery Tools

Steganalysis Tools

LACK is the method of Steganography where in the audio packets are intentionally delayed and are actually used for sending secret messages. Usually when the packet does not reach the destination or is delayed by large amount of time that becomes unusable for reconstruction at the receiver, it is considered as lost packet and discarded. This feature of VoIP service can be used for Steganography and is called LACK. For intentional users, the intentionally delayed packets are steganograms and used for sending secret messages, while for unaware users, the delayed packets are discarded by default and the existence of secret message is simply invisible.

Scenario (1) shows that N4 is chosen as delayed audio packet for sending steganogram and is sent after a certain delay as seen in scenario (2). In scenario (3), an unaware user is considered on the receiver side, and hence the receiver drops the packet and the packet is lost by default. Scenario (4) has an intentional receiver that considers the delayed packet for steganogram and the secret communication takes place. Performance based on different parameters that needs to be considered will be covered in this project and results in terms of efficiency, packet loss and other parameters will be presented.

There are imperfections in the transmission medium that leads to natural susceptibility of data distortion. Lot of noise and interferences in communication system exists. Taking advantage of these defects, HICCUPS is implemented as steganographic method for VoIP calls. It works on basis of bandwidth allocation of shared medium networks, where wireless networks, which are more vulnerable to data distortion, are targeted. HICCUPS may be applied to cryptosystems working in the network susceptible to interception such as LAN of large range. The numerical value assigned to the data packet based on number of bits in a packet is called checksum, which is used to authenticate whether the data ...