In early days,  information’s 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.  

                                                                                                        

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