Image Encryption using Variable Length Blocks and Variable Length PK

Abstract

The colored digital image is one of the most important and popular types of digital data for use in many vital applications, which requires the provision of safe methods to protect it from penetration operations and protect it from tampering and data thieves. In this research paper, a new method for protecting digital images of various types will be presented, which is characterized by ease of implementation and providing a high degree of security and protection for the digital image. A secret color image known only by the sender and receiver will be used as an image_ key, this image_key will be used to generate a private key to encrypt-decrypted any color image by applying image resizing. The private key will be variable, and will match the image block size. The image to be encrypted-decrypted will be divided into blocks, the block size will be variable and agree upon between the sender and receiver. The proposed method will be implemented, the obtained results will be analyzed to prove the efficiency, security level and quality parameters provided by the proposed method.

Improving Standard Methods of Message Cryptography

“…Messages may be private or secret, thus they require a high level of protection when using unsecure communication environment [22][23][24][25][26]. One of the most popular techniques to protect the secret messages is data cryptography, which means encrypting the message before sending it and decrypting the message after receiving it.…”

Bits Substitution to Secure LSB Method of Data Steganography

“…It provides a higher degree of security that enables the protection of the image (stego) that contains the message from attacks by people who are not authorized to view confidential information. The accuracy and clarity of the image will not change much when the message is included in an image using LSB method, a substitution sequence will be used to create a PK key, this will provide the LSB method with the required security to protect the embedded secrete message [30][31][32][33][34][35][36][37][38][39][40][41].…”

“…-The pixel in the carrier image is slightly affected by the process of hiding the secret message, as the pixel value changes within the range -1 and +1 (see table 1), which is a very small value that cannot be noticed with the naked eye, and by this the MSE between the carrier and stego images will be small, while the PSNR and CC between them will be high [31][32][33][34][35][36][37][38][39][40].…”

Text Files Protection using Chaotic Logistic Keys

“…A good method of data cryptography must provide a low quality in the encryption phase and a high quality in the decryption phase [43][44][45][46][47][48][49][50]. The quality (see figure 1) between two files can be measured by the quality parameters MSE, PSNR, CC and NSCR, the method of cryptography must satisfy the requirements listed in table 1 [22][23][24][25][26][27][28][29][30]: The selected PK to be used in encryption and decryption phases must be kept in secret between the data sender and the data receiver. This key is to be used to generate the secret key (keys) needed to apply text file encryption and decryption.…”