In the second step of the algorithm, the concatenated images are regarded as one stream of bytes, and the encryption performed is both key dependent and data dependent. A single bit, call it fixBit, is chosen by a function based on the key. In this paper, this function adds some digits of the key and takes the remainder of dividing this sum by 8. A shuffle vector is constructed by listing the numbers of bytes which have the value of bit number fixBit equal to zero, followed by the numbers of bytes which have the value of bit number fixBit equal to one. This vector gives a mapping that specifies the new location of each byte in the array. This step is repeated for several iterations. Each iteration uses a different fixBit and applies the same steps to the new array that resulted from the preceding iteration. The number of iterations, k, is a small number chosen by a key-dependent function.
Public-key encryption uses two distinct but mathematically related keys - public and private. The public key is the non- secret key that is available to anyone you choose (it is often made available through a digital certificate). The private key is kept in a secure location used only by the user. When data are sent they are protected with a secret-key encryption that was encrypted with the public key. The encrypted secret key is then transmitted to the recipient along with the encrypted data. The recipient will then use the private key to decrypt the secret key. The secret key will then be used to decrypt the message itself. This way the data can be sent over insecure communication channels .
This paper aims at improving the level of security and secrecy provided by the digital color signal-based imageencryption. The imageencryptionand decryption algorithm is designed and implemented to provide confidentiality and security in transmission of the image based data as well as in storage. This new proposed encryptionalgorithm can ensure the lossless of transmissions of images. The proposed encryptionalgorithm in this study has been tested on some images and showed good results.
A novel optical encryption method is proposed in this paper to achieve 3-D imageencryption. This proposed encryptionalgorithm combines the use of computational integral imaging (CII) and linear-complemented maximum- length cellular automata (LC-MLCA) to encrypt a 3D image. In the encryption process, the 2-D elemental image array (EIA) recorded by light rays of the 3-D image are mapped inversely through the lenslet array according the ray tracing theory. Next, the 2-D EIA is encrypted by LC-MLCA algorithm. When decrypting the encrypted image, the 2-D EIA is recovered by the LC-MLCA. Using the computational integral imaging reconstruction (CIIR) technique and a 3-D object is subsequently reconstructed on the output plane from the 2-D recovered EIA. Because the 2-D EIA is composed of a number of elemental images having their own perspectives of a 3-D image, even if the encrypted image is seriously harmed, the 3-D image can be successfully reconstructed only with partial data. To verify the usefulness of the proposed algorithm, we perform computational experiments and present the experimental results for various attacks. The experiments demonstrate that the proposed encryption method is valid and exhibits strong robustness and security.
In selective encryption some content of the image is encrypted. It reduces the execution time because it encrypts only a part of the image. Consequently, selective encryption is sometimes called partial encryption. This algorithm provides security to the imageand in the same time, some part of the image is visible. One of the use of this algorithm is in medical field, now a days the doctors are consulting the other doctors abroad, this algorithm can really help those. The medical image data is different from other visual data for multimedia applications. Since the lossy data cause some negative misdiagnosis.
Encryptionand watermarking are complementary lines of defense in protecting multimedia content. Recent watermarking techniques have therefore been developed independent from encryption techniques. In this paper, we present a hybrid image protection scheme to establish a relation between the data encryption key and the watermark. Prepositioned secret sharing allows the reconstruction of different encryption keys by communicating different activating shares for the same prepositioned information. Each activating share is used by the receivers to generate a fresh content decryption key. In the proposed scheme, the activating share is used to carry copyright or usage rights data. The bit stream that represents this data is also embedded in the content as a visual watermark. When the encryption key needs to change, the data source generates a new activating share, and encrypts the corresponding data with the key constructed from the new activating share. Before transmission, the encrypted data is embedded in a multimedia stream. Each receiver can extract the encrypted data from the host image, and decrypt this data after reconstructing the same key. Our presentation will include the application of the scheme to a test image, and a discussion on the data hiding capacity, watermark transparency, and robustness to common attacks. Keywords: discrete cosine transform, discrete wavelet transform, and international data encryptionalgorithm (IDEA), Bit correct ratio.
Visual cryptography technique for black and white images (Basic) introduced by Naor and Shamir . Any visual secret information ( pictures, text, etc) is considered as imageandencryption is performed using simple algorithm to generate n copies of shares depending on type of access structure schemes[2, 6].The simplest access structure is the 2 out of 2 scheme where the secret image is encrypted into 2 shares and both needed for a successful decryption. These shares are random dots without revealing the secret information.
The proposed algorithm took Logistic map parameter μ and iterative initial value x0, and Hénon map initial value (x, y, z) as the original key, iteration time N. Each digit has 14 digital numbers, therefore, the key space is 10 14×6 =10 84 , the key space will be greater, and therefore, the algorithm has a strong resistance against attack of exhaustion as the key space will be greater. For example diffusion key space consists of 3 initial parameters (3-sub keys). The key space of each one is equal 256 bit and the attacker needs 3*2 256 operations to find the exact key. If the attacker employs 1000 million instructions per second of computer processing to guess the key by brute force attack, the computational load in years is:
Abstract— This paper describes the results of efficient measuring methods whereby the encryption capability of four algorithms are evaluated. Specifically this work focuses on measuring the encryption quality, the memory requirement and the execution time of the encryption as an indicator to the usage of the software and the hardware. Also, the security analysis of these schemes is investigated from cryptographic viewpoint; statistical and differential attacks. A number of requirements are therefore identified upon which the algorithms are evaluated. The results of the efficient measuring methods show that each algorithm has its own strengths and weaknesses and no single encryption mechanism is able to get the maximum security with minimum execution time. The paper proposes that it may be possible to develop new algorithms providing adequate means of efficiency with acceptable security.
Umaparvathi and Varughese in  presented a comparison of the most commonly used symmetric encryption algorithms AES (Rijndael), DES, 3DES and Blowfish in terms of power consumption. A comparison had been conducted for those encryption algorithms using different data types like text, image, audio and video. The various encryption algorithms had been implemented in Java. In the experiments, the software encrypts different file formats with file sizes (4MB - 11MB). The performance metrics like encryption time, decryption time and throughput had been collected. The presented simulation results showed that AES has a better performance than other common encryption algorithms used. Since AES had not showed any known security weak points in the presented study, this makes it an excellent candidate. 3DES showed poor performance results since it requires more processing power. Since the battery power is one of the major limitations in MANET nodes, the AES encryptionalgorithm is the best choice.
Abstract- The advent of wireless communications, both inside and outside the home-office environment has led to an increased demand for effective encryption systems. The beauty of encryption technology comes out in more pronounced way when there is no absolute relation between cipher and original data and it is possible to rebuild the original image in much easier way. As chaotic systems are known to be more random and non-predictable, they can be made utilized in achieving the encryption. The transposition technology of encryption systems requires scrambleness behaviour in order to achieve the encryption of the data. This scrambleness behaviour can be derived from the randomness property of chaos which can be better utilized in the techniques like transposition system. In wireless communication systems, bandwidth utilization is an important criterion. In order to use encryption system in wireless communication; key space plays an important role for the efficient utilization of the bandwidth. In this paper we present a chaos based encryptionalgorithm for images. This algorithm is based on pixel scrambling where in the randomness of the chaos is made utilized to scramble the position of the data. The position of the data is scrambled in the order of randomness of the elements obtained from the chaotic map and again rearranged back to their original position in decryption process. The same algorithm is tested with two different maps and performance analysis is done to select best suited map for encryption.
We propose a new non-chaos based imageencryption scheme using a key of 128-bit size. In the algorithm, image is partitioned into several key based dynamic blocks and each block is passed through the eight rounds of diffusion as well as substitution process. In diffusion process, sequences of block pixels are rearranged within itself by a zigzag approach whereas block pixels are replaced with another by using difference transformation in substitution process. We have carried out an extensive security and performance analysis of the proposed imageencryption technique using various statistical analysis, key sensitivity analysis, differential analysis, key space analysis, speed performance, etc. Based on the results of our analysis, we conclude that the proposed imageencryption technique is perfectly suitable for the secure image storing and transmission.
Many image in recent years are transmitted via internet and stored on it. Maintain the confidentiality of these data has become a major issue. So that encryption algorithms permit only authorized users to access data which is a proper solution to this problem.This paper presents a novel scheme for imageencryption. At first, a two dimensional logistic mapping is applied to permutation relations between image pixels. We used a fractal image as an encryption key. Given that the chaotic mapping properties such as extreme sensitivity to initial values, random behavior, non-periodic, certainty and so on, we used theses mappings in order to select fractal key for encryption. Experimental results show that proposed algorithm to encrypt image has many features. Due to features such as large space key, low relations between the pixels of encrypted image, high sensitivity to key and high security, it can effectively protect the encrypted image security.
Step iii. Then uniform scrambling is applied onto the image IW’’ where the pixels in the same block of original image is distributed into all the blocks of scrambled imageand the every block has one pixel at least, without regarding to the order of the pixels appearance, accordingly all the pixels in the same block of scrambled image come from different blocks of original image. Figure below shows that all the pixels in the first block of the original image are distributed into all the blocks of the scrambled image. Thus, the ideal block numbers is N for an original image of size NxN. After scrambling, the resultant would be a new image IW’’’.
et al used Discrete Wavelet Transform for encrypted images . Younes and Jantan introduced the concept of the block- based transformation encrypted imagealgorithm . Mao et al used a new scheme of chaotic Baker maps imageencryption . Wu et al studied and used the concept of Sadouka matrix in encrypted image . Jayant and Roy proposed the method of break correlation among neighboring pixels . Alghamdi and Hanif Ullah used chaotic function for iris encryptionimage . Jolfaei and Mirghadri Surveyed and studied the Salsa20 scheme for imageencryption  .Ye and Zhou proposed the concept of chaos-based imageencryption scheme . Dey introduced mixed and Vernam permutation algorithm . Landge et al proposed the method of 64-bits blowfish . Al-Husainy proposed algorithm which mixed boolean operations andimage hiding . Shreef and Hoomod used the interpolating functions technique to encrypt image . Ye proposed an algorithm based on chaos and diffusion mechanism with permutation . Al-Rammahi et al introduced an encrypted algorithm based on the analysis of singular value decomposition . Lin and fuh introduced Barcode Image Decoding in two dimensions .
The proposed imageencryptionalgorithm has two major steps. Firstly, the correlation among the adjacent pixels is disturbed completely as the image data have strong correlations among adjacent pixels. For image security and secrecy, one has to disturb this correlation. To achieve this, a block and stream based image shuffling scheme is proposed using the three chaotic maps mentioned above. Then the pixel values of the shuffled image are modified by employing Henon map. Encryption is done in two stages confusion and diffusion.
Imageencryption is an important and effective technique to protect image security. In this paper, a novel imageencryptionalgorithm combining Julia sets and Hilbert curves is proposed. The algorithm utilizes Julia sets’ parameters to generate a random sequence as the initial keys and gets the final encryption keys by scrambling the initial keys through the Hilbert curve. The final cipher image is obtained by modulo arithmetic and diffuse operation. In this method, it needs only a few parameters for the key generation, which greatly reduces the storage space. Moreover, because of the Julia sets’ properties, such as infiniteness and chaotic characteristics, the keys have high sensitivity even to a tiny perturbation. The experimental results indicate that the algorithm has large key space, good statistical property, high sensitivity for the keys, and effective resistance to the chosen-plaintext attack.
x Tunability: It could be very desirable to dynamically define the encrypted part and the encryption parameters with respect to different applications and requirements. Static definition of encrypted part and encrypted parameters limits the usability of the scheme to a restricted set of applications. Tunability factor can have one of the values ‘yes’ or ‘no’.
The Internet as a whole does not use secure links, thus information in transit may be vulnerable to interruption as well. The important of reducing a chance of the information being detected during the transmission is being an issue in the real world now days. The Digital watermarking method provides for the quick and inexpensive distribution of digital information over the Internet. This method provides new ways of ensuring the sufficient protection of copyright holders in the intellectual property dispersion process. The property of digital watermarking images allows insertion of additional data in the image without altering the value of the image. This message is hidden in unused visual space in the imageand stays below the human visible threshold for the image. Both seek to embed information inside a cover message with little or no degradation of the cover-object. In this paper investigate the following relevant concepts and terminology, history of watermarks and the properties of a watermarking system as well as a type of watermarking and applications. We are proposing edge detection using Gabor Filters. In this paper we are proposed least significant bit (LSB) substitution method to encrypt the message in the watermark image file. The benefits of the LSB are its simplicity to embed the bits of the message directly into the LSB plane of cover-imageand many techniques using these methods. The LSB does not result in a human perceptible difference because the amplitude of the change is little therefore the human eye the resulting stego image will look identical to the cover imageand this allows high perceptual transparency of the LSB. The spatial domain technique LSB substitution it would be able to use a pseudo-random number generator to determine the pixels to be used for embedding based on a given key. We are using DCT transform watermark algorithms based on robustness. The watermarking robustness have been calculated by the Peak Signal to Noise Ratio (PSNR) and Normalized cross correlation (NC) is used to quantify by the similarity between the real watermark and after extracting watermark.
Although Cloud computing keeps growing, its users are aware and cite security guaran- tees as their main concern when adopting such services (Columbus, 2017a; Meeker, 2017). These concerns are not without a cause; in recent years, several cases of privacy breaches have surfaced. Some of these are intended company policies, such as using data assumed private for advertising purposes (Rushe, 2013); other breaches may also be the result of government-ordered surveillance programs (Cook, 2016; Greenwald and MacAskill, 2013). These kind of leaks aﬀect not only companies, but also individual users (Hough, 2010; Lewis, 2014; Turner, 2016). Particularly sensitive information, like health records, have also been the subject of several attacks (HCA News, 2018; O’Hara, 2017; Roston, 2017); with the recent growth in personal health apps usage (Khalaf, 2014; Meeker, 2017), the need for data security increases. In light of these concerns and news, Cloud services present themselves as a double-edged sword for its users: how to leverage the advantages of the Cloud without compromising privacy and security?