Simultaneous encryption of multiple images using pseudo-random sequences generated by modified Newton-Raphson technique

A multiple image encryption using pseudo random (PR) sequence is proposed in this article. A non-chaotic technique pillared on modified Newton- Raphson method is applied to produce the PR sequence. To do that, a tangent is drawn to the given function from a middle point of two seed values. The fraction part of the function computed at the intersecting point of the tangent with X − a x i s is applied to produce the PR sequence. NIST test says in support of the randomness of the PR sequence. The encryption of the plaintext images are achieved by row wise gray value substitution and multi image iterated addition with bitwise circular shift operation. The process makes the plaintext images noise like. Simulation results are presented to exhibit the validity of the proposed method and security analysis proves its immunity against different attacks. Comparison with some recent state of the art chaotic map based schemes provides it a strong base in multiple-image encryption technique.