Certain new approaches for image encryption using scan pattern based pixel permutation and random number

Abstract

Internet is an important entity in the daily life of people in many ways, which allows people in different parts of the world to share all types of information. Information security is a vital issue for data storage and exchange of sensitive digital data through Internet. The need for data privacy and security has become essential in telecommunication because of increased security threats. Cryptography provides an effective solutionfor securing data communicationsover the public networks.Transmissionof multimediadata over the Internet has increased due to the development of simple and easy to use digital communicationtechniques. Among the different types of multimedia data, images are transmitted very oftendue to their wide usage in different applications. In fields like medicine, defence, space, education,and other industrial domains, massive amount of information are gathered, stored, and transferred in the form of digital images.Data security is an inevitable issue because of the variety ofsoftware and hardware vulnerabilities present in the network. Thus, it is essential to protect the sensitive image data from unauthorized disclosure. Thetraditional and pioneer cryptosystems like Data Encryption Standard (DES), Advanced Encryption Standard (AES), and International Data Encryption Algorithm (IDEA) are the frequently used algorithms to encrypt textual data.The algorithms that are good for the encryption of textual data are not suitable for the encryption of multimedia data due to large data size and execution time constraints. Image encryption isa techniqueused to share sensitive image information through insecure networks with confidentiality. viBased on permutation the image encryption methodsareclassified as bit permutation, pixel permutation,and block permutation.In bit permutation, the bits of each pixel of the image are permuted with the key chosen from a set of keys. In pixel permutation, the pixel position of the image is rearranged using the key selected from a set of keys. In the case of block permutation, the image is divided into blocks and these blocks are permuted based on a random key.Typically, pixel permutation based image encryption methods use scan patterns for image scrambling. Scan pattern is a formal language-based two dimensional spatial-accessing methodology which can efficiently specify and generate a wide range of scanning paths.Primarily, random number is used to offer substitution by using the simple and efficient bitwise XOR operation.Good cryptographic techniques require good random numbers, and hence, the random numbers play an important role in image encryption.In general, diffusion is achieved by repeatedly performing several permutations and confusion is achieved by substitution.The objective of this research is to develop certain simple and effective image encryption methods using scan pattern based pixel permutation and random number.In image encryption, bitwise XOR operation is used to replace a pixel value with another pixel valueto provide confusion property.To implement this, random numbers are mainly used in image encryption. In this research, six new scan patternsfor pixel permutation, two methods for generating random key stream, and a method to generate true random numbers are proposed.In the proposed work, the following are the six new scan patterns generated by using certain novel concepts.The concept of Matrix Reordering(MR)provides well permuting rows and columns of a matrix. In the proposed method, the pixel permutation has been carried out by using scan patterns