Improving the security of LSB image steganography

Abstract

Steganography is the technique of hiding secret data (message) within any media such as digital color image. In this paper we will merge steganography process with cryptography process in order to increase the security of the proposed method. The steganography process will based on LSB method, while the cryptography process will based on generating a huge private key and selecting a special function for encryption decryption. The proposed method will be implemented in order to calculate some performance parameters to prove the efficiency of the proposed method.

Using Logical Operations to Secure LSB2 Data Steganography

“…Many methods are used for data steganography [17], [18]] many of them such as LSB2 are based of least significant bit (LSB) methods [19], [20]. LSB2 method provides a higher capacity than LSB method, because it reserves 4 bytes from the carrier image to hide one character from the secrete message, as shown in figure 2 the least two significant bits from the carrier byte are used to hide two bits from the message character [21]. LSB2 method is very simple in handling hiding process (see figure 3) and handling extraction process (see figure 4), it requires a small times to implement these processes, also it provides a good quality parameters by minimizing the values of MSE and maximizing the values of PSNR [22].…”

“…The process of steganography must not add noticeable updates to the stego_image, thus the changes in the stego_image must not be noticed by human eyes. Stego_method must provide the following features [21], [22]:…”

Image Blocking to Hide Secret Message

“…Instead of using the whole color image we can select a block from the image to be used to hold the secret message, to do this we have to select the block size by defining the number of rows and number of columns to form a block, these numbers must be kept in secret to raise the security of LSB method. Figure 3 shows an image example of size 165x247x3, while figure 4 shows the obtained blocks for this image [22], [23].…”

“… Color image is widely available and can be obtained easily [19], [20].  Ease of processing color digital image [21][22][23][24][25][26][27][28][29][30][31][32].  The ability to use a specific part of the image to hide the message.…”

Data Steganography Using Embedded Private Key

“…Many methods were proposed for data steganography [19], [20], [21], most of them are based on least significant bit (LSB) method of data hiding, and here in this paper we will use LSB2 method because it has good features such as doubling the hiding capacity, providing low value for MSE and high value for PSNR [22], [23], [24].…”