IMAGE ENCRYPTION FOR SECURE INTERNET TRANSFER

— Security is a crucial side to preserve the confidentiality of information such as pictures and text. The probability of an assailant attempting to access the image in the course of transferring process is high as assailant may get hold of important data. Therefore, encryption methods are used for securing the data. A novel image encryption algorithm that is a combination of the AES algorithm and the chaos sequence is proposed in this paper. The project will use AES for encryption and decryption of the image transfer because AES is capable of solving problem that cannot be resolved by different algorithms. The original image is transformed into cipher-image using a share secret key and this process is called encryption while the reverse of encryption process is known as decryption. This method’s sensitivity to the initial values and input image, even the tiniest changes within these values will result in significant changes in the encrypted image. We show that this approach can shield the image against different attacks exploitation using histogram analysis.


I. INTRODUCTION
Now a day's, technology has become an essential factor in our everyday life.The usage of devices like laptop, computer and mobile for communication as well as for data storage and transmission has inflated.This has led to a retardant in security.Cryptography is one of the ways of securing the data.The process of encryption is dispensed.The encrypted data is not liable to the unauthorized user.
There are numerous cryptographical techniques offered for securing crucial information like Data Encryption Standard (DES), Triple DES, RC4 and Advanced Encryption Standard (AE).The algorithm converts the text or image into cipher information and the other way around.This process is known as encryption and decryption.
There are generally two forms of cryptographical mechanisms: symmetric key cryptography within which the same key is used for both decryption and encryption.And the other type is asymmetric key cryptography, within which two different keys are used for encryption and decryption.Symmetric key algorithm is much faster and easier for implementation and needs less processing power as compared to asymmetric key algorithm.
Advanced Encryption Standard (AES) is a symmetric block cipher encryption method.This means that it operates on fixed-length chunks of data (for example, blocks), applying constant transformation to every block.The transformation can be controlled by the employment of encoding key.Block ciphers use symmetric keys, which mean that the same key used to encrypt data is also used to decrypt it.
Several standard encryption algorithms have already been proposed for the aim of text encryption.Due to redundancy of the visual data, correlation between adjacent pixels and, the high volume these algorithms have terribly low security and high encoding time.Therefore, these algorithms are not ideal for the image encryption.Numerous image encryption algorithms are introduced to overcome these issues.Generally, many evaluation criteria should be thought for image encryption, together with the data entropy, correlation between adjacent pixels.For the algorithm to resist different attacks performed by the assaulter, the values of this criteria ought to meet the required expectancy.This paper proposes an image encryption algorithm, combining the chaos system and standard encryption algorithm of AES.First, the encryption key is built using chaos system, and then, the image is encrypted by using the proposed algorithm.The subsequent sections make a case to the results in detail.

II. RELATED WORK
A technique for image encryption using digital signature [1].The digital signature of the initial image is added to the encoded version the initial image.image is encoded using an appropriate error management code, such as a Bose-Chaudhuri Hochquenghem (BCH) code.At the receiver end, after the image is decrypted, the digital signature will be accustomed to verify the genuineness of the image.
A novel image encryption algorithm supported on selfadaptive wave transmission [2].Describes a fast image encryption algorithm based on self-adaptive wave transmission that uses one half of image data to encrypt the opposite half of the image.The method to achieve the high security will be continued.During encryption, an image is equally divided into two parts, wave transmission encryption technique with four waves is employed to encrypt both the parts whose amplitudes are determined by the opposite one.Since the amplitude of the wave may be too overlarge, it is not convenient to represent it in computer due to computation complexity.
A digital image encryption algorithm based on chaotic mapping [3].Proposes the enciphering using the chaotic technique.Distinctive data is extracted.Add-image feature procedure is applied here.The chaotic number which is selected by the sender is the key here.Chaotic number and the distinctive data chosen generates the chaotic sequence.The algorithm will be able to restore the original data with no loss of data.
A novel selective encryption method for securing text over mobile ad hoc network [4].This paper proposes a method referred to as selective encryption for securing the text over wireless Networks.This selective encryption method encrypts only the necessary texts instead of encrypting the entire text.Usually in scenarios like wireless network devices, it is tough for a sensor to spend more computational cost on encrypting and decrypting just to use the battery.Hence by applying the selective Encryption Method over the Ad hoc networks the processing interval is reduced that additionally will increase the scalability of data transmission.
Text to image encryption technique using RGB substitution and AES [5].This paper proposes a way of converting a text to image and then encryption is applied to that.RGB substitution method is employed to convert the text to an image where each character of the text is appointed to a pixel randomly and an image is formed through it.The image is then encrypted using AES Algorithm and therefore decryption occurs in reversed manner.This proposed technique is extremely secure because even if the assailant tries to decrypt the output would be an image.[6].This paper proposes the various chaotic map techniques for image encryption.The 2D chaotic cat Map is generalized to make 3D cat map, applying the 3D cat map on the image that needs encryption helps to shuffle the image pixels and positions.Shuffling the pixels is done using two stages, these stages are namely confusion and diffusion.Due confusion occurs due to shuffling and it also makes the distinction between the plain image and cipher image.So that the resistance to attacks and security is increased that makes the image secured.

Survey of 3D Chaotic Map Techniques for Image Encryption
Rapid Encryption Method based on AES Algorithm for Grey Scale HD Image Encryption [7].To handle the high computational load of the AES algorithms the number of rounds of AES are reduced to just one round, and to encrypt greyscale high-definition images a new S-box method is proposed.The reduction to only a single round showed a really vital attenuation in the encryption time of the algorithm by 1/10 and reduced the ROM used by 256 bytes.

A New Modified Version of Advanced Encryption Standard
Based Algorithm [8].An AES modification by adjusting the Shift Rows transformation was introduced by this paper.The idea of shifting of rows is from the value in the state ([0][0]) whether the value of the state is odd or even.The result shows that the proposed transformation provides better encryption time because it does not have any surplus operations.
Data security-modified AES algorithm and its applications [9].In this paper, initially the original image is used as the input.Then, the rows and columns of the image's pixels are right-