Least Significant Bit 

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... the application the user first specifies the data that they would like to hide, which can be in any file format. The application then encrypts this data using the recipient‟s RSA public key. Once the encrypted data is obtained, the procedure described in the following paragraph is repeated for each image in a user‟s image library. Each bit of the encrypted data is compared to the least significant bit of the pixel bytes in an image. The comparisons are made starting from the first byte in the image until the last byte that permits all the data to be hidden in that image. The application cycles through the pixels of the image looking for the block of bytes those results in the least number of LSB changes. Least significant bit insertion is a common, simple approach to embed information in a cover file [7]. Usually, three bits from each pixel can be stored to hide an image in the LSBs of each byte of a 24-bit image. The resulting stego-image will be displayed indistinguishable to the cover image in human visual system [18]. The last bit of the byte is selected as least significant bit in one bit LSB as illustrated in Figure 2 because of the impact of the bit to the minimum degradation of images [32]. The last bit or also known as right-most bit is selected as least significant bit, due to the convention in positional notation of writing less significant digit further to the right [20]. In bit addition, the least significant bit has the useful property of changing rapidly if the number changes slightly. For example, if 1 (binary 00000001) is added to 3 (binary00000011), the result will be 4 (binary 00000100) and three of the least significant bits will change (011 to 100). There are numbers of steganograpic tools which employ LSB insertion methods available on the web. For example, S-Tools take a different approach by closely approximating the cover image which may mean radical palette changes. Instead, S-Tools reduce the number of colours while maintaining the image quality, so that the LSB changes do not drastically change colour values. Another tool which is using LSB manipulation is EzStego. It arranges the palette to reduce the occurrence of adjacent index colours that contrast too much before it inserts the message. This approach works quite well in gray-scale images and may work well in images with related colours [18]. On the other hand, StegCure keeps the advantage of S-Tools and EzStego that is maintaining the image quality, but it can prevent the attack from hackers by restricting user to have only one attempt to perform destego method. If the user has used the wrong destego method for the first time, there is no second attempt to recover the hidden data in the image even though the user has chosen the correct destego ...