In divided into units of 4 bits to permute

In early days, informations are shared in the form of text
messages. To secure those messages from unauthorized person
AES and DES algorithm are used for hiding the information.
Later, due to the development of technologies peoples starts
to sending the information in the form of images. In order to
secure the images from hackers and unknown person become
a serious challenge in this digital world. AES and DES
algorithm are not suited for multimedia information due to
some characteristics like high data and high correlation among
the pixels. Those two algorithms are typically designed for the
purpose of textual information.1-3 Encryption is a efficient
method to solve these issues. Encryption is a process which
uses finite set of instruction called an algorithm to convert
original image to an encrypted form. A chaotic system is rich
in significance and in implication because of ergodicity and
pseudorandom sequences. These structures are too complex
and difficult to analyze . one round of permutation and
substitution are done to get the accurate result. Here, the
permutation and substitution are done by row by row / column
by column instead of pixels by pixels in order to increase
the speed of encryption4.Wang Xing-Yuan at5 presented
a image encryption based on chaotic system and cycle shift.
Cycle shift is a suitable for scrambling the images and can
also change the values in image pixels. It has large key space,
high level security encryption scheme and resistive against
known attacks. In6Based on RCA combining chaos , In
confusion step,each pixel of image is divided into units of
4 bits to permute for permutation. Logistic map is used for
generating the keys and 2D RCA is used to achieve the bit
level at diffusion stage. It belongs to the symmetric system.
Enayatifar at al7 Advanced their work by using tinker bell
chaotic map, DNA sequence and CA simultaneously. Here CA
is used to generate pseudorandom numbers . For encryption
chaotic map is combined with Tinkerbell chaotic mapping.
Wang Leyuan8 proposed a color image encryption based on
two complex chaotic system. The main purpose of this paper
is to mix RGB channel by using pseudorandom numbers . So,
in confusion step pixels are modified by using 2D process and
one step process. The mix of RGB channel leads to multilevel
encryption.