Edinburgh Napier University

  In modern era, multimedia technologies have been developed significantly. Multimedia data such as audio, video and image transfers over the internet is open and insecure. Security is required for storage and transmission of digital images to avoid from unauthorized entities. A number of encryption schemes have been developed for security of multimedia data over insecure channel. So, there is a real need to compare encryption schemes that which technique is better for multimedia application. This paper presents the estimation for the good image encryption algorithm. Chaos based image encryption algorithm are used now a days because of better security and good performance. Behaviour of chaotic system is nonlinear, deterministic and sensitive to initial condition. A number of parameters, like correlation coefficient, information entropy, compression friendliness, number of pixels change rate, average intensity and unified average change intensity etc., are used to check the quality of cipher-text image. This work is review of two image encryption schemes, namely Compression Friendly Encryption Scheme (CFES) and Chaos Based Encryption Scheme (CBES).