Abstract: Steganography is derived from the Greek word steganographic which means covered writing. It is the science of secret communication. The goal of steganography is to hide the existence of the message from unauthorized party. The modern secure image steganography presents a task of transferring the embedded information to the destination without being detected by the attacker. Many different carrier file formats can be used, but digital images are the most popular because of their frequency on the Internet. For hiding secret information in images, there exist a large variety of steganographic techniques some are more complex than others and all of them have respective strong and weak points. In this thesis a process to Increase security of hidden data in Image and Prevent data extraction has been presented. We will encrypt data by use key1 and hide data using LSB technique using key2. In the LSB approach, the basic idea is to replace the Least Significant Bits (LSB) of the cover image with the Bits of the messages to be hidden without destroying the property of the cover image significantly. The LSB-based technique is the most challenging one as it is difficult to differentiate between the cover-object and stego-object if few LSB bits of the cover object are replaced. By using the key, the chance of getting attacked by the attacker is reduced.
Keywords: TSFS, LSB (Least Significant Bit), Hidden message.