Investigation on diffusion and confusion based image encryption algorithms

Abstract

With the rapid improvement in information technology security is a major concern in the transmission of digital data over various networks and data storage Security mechanisms must be implemented to provide the required protection to the transmitted data Image encryption is a technique which provides security to images by transforming the image to an unreadable format Access control privacy validation and copyright protection are an integral part of this process Three diverse approaches to shield computerized information from unapproved spying are cryptography steganography and watermarking Among these three systems cryptography has turned out to be one of the significant approaches to give maximum security Cryptography manages the advancement of procedures for changing over data amongst coherent and incoherent structures It manages the substance secrecy and access control through encryption and decryption algorithms which are operated by keys Encryption and decryption techniques that use the same secret key are private key cryptography Alternately keys are different for both encryption and decryption such cryptographic methods are known as public key cryptography Any crypto system must satisfy confusion and diffusion property to provide security Confusion property substitutes the pixel values whereas diffusion property rearranges the pixels of an image The limitation of conventional encryption methods are i takes more time to encrypt the plain image ii the size of decrypted plain text must be equal to the original text size Many researchers presented chaos-based image encryption system and selective image encryption schemes for a faster execution of encryption/decryption Also genetic operator based encryption algorithm is presented in the literature in which the level of difficulty set for an unauthorized individual to break the encryption is heightened Nowadays transformation based image encryption algorithms are presented newline