Abstract: This paper proposes a new hybrid security algorithm called RC4-DNA-Alg. It combines the symmetric stream cipher RC4 algorithm with DNA-indexing algorithm to provide secured data hiding with high complexity inside steganography framework. While RC4 represent one of the widely used algorithms in network security protocols such as Secure Sockets Layer (SSL), a DNA cryptography considered as a modern branch of cryptography that combines the traditional cryptographic techniques with the power of the genetic material The performance evaluation of the proposed algorithm is measured based on three parameters (conditional entropy, randomness tests and encryption time). The result shows outperformance in security and distorted in hybrid Cipher compared to the native RC4.

Abstract: The content of the SMS is very crucial. It consists of an imperative information. Unknown participants can not retrieve it. To protect the SMS content, the sender must provide the unique character before it is completely sent. The cryptography technique is needed. The plaintext has to be encrypted before transmitted. The one-time pad method can be applied to the plaintext. The one-time pad is one of the easiest cryptography methods. It turns the plaintext into the ciphertext by doing XOR operation to every character. It generates the new ASCII as the cipher character.

Abstract: Cryptography is used for secure communication over a media in presence of third party adversaries. If proper encryption algorithm is not used then it will be easy for third party hackers to decrypt the secret message very easily. This paper presents a strong hybrid image encryption and decryption algorithm. In order to make the encrypted image harder to decrypt Arnold's cat map is combined with two more algorithms, Criss-cross and Random Shuffling technique to make an altogether relatively stronger permutation cipher. Steganography is used to conceal the encrypted secret file within the cover image to get the stego image. In this paper the steganography algorithm will consist of a combination of Continuous Raster C pattern and LSB algorithm. LSB algorithm will be applied based on the scan pattern. The experimental results demonstrate that the image encryption algorithm and steganography algorithm together incorporate the advantages of great level of security.

Abstract: In this paper, we present a novel technique for security of two-dimensional data with the help of cryptography and steganography. The presented approach provides multilayered security of two-dimensional data. First layer security was developed by cryptography and second layer by steganography. The advantage of steganography is that the intended secret message does not attract attention to itself as an object of scrutiny. This paper proposes a novel approach for encryption and decryption of information in the form of Word Data (.doc file), PDF document (.pdf file), Text document, Gray-scale images, and RGB images, etc. by using Vigenere Cipher (VC) associated with Discrete Fourier Transform (DFT) and then hiding the data behind the RGB image (i.e. steganography). Earlier developed techniques provide security of either PDF data, doc data, text data or image data, but not for all types of two-dimensional data and existing techniques used either cryptography or steganography for security. But proposed approach is suitable for all types of data and designed for security of information by cryptography and steganography. The experimental results for Word Data, PDF document, Text document, Gray-scale images and RGB images support the robustness and appropriateness for secure transmission of these data. The security analysis shows that the presented technique is immune from cryptanalytic. This technique further provides security while decryption as a check on behind which RGB color the information is hidden.

Abstract: CAESAR has caused a heated discussion regarding the merits of one-pass encryption and online ciphers. The latter is a keyed, length preserving function which outputs ciphertext blocks as soon as the respective plaintext block is available as input. The immediacy of an online cipher affords a clear performance advantage, but it comes at a price: ciphertext blocks cannot depend on later plaintext blocks, limiting diffusion and hence security. We show how one can attain the best of both worlds by providing provably secure constructions, achieving full cipher security, based on applications of an online cipher around blockwise reordering layers. Explicitly, we show that with just two calls to the online cipher, prp security up to the birthday bound is both attainable and maximal. Moreover, we demonstrate that three calls to the online cipher suffice to obtain beyond birthday bound security. We provide a full proof of this for a prp construction, and, in the ±prp setting, security against adversaries who make queries of any single length. As part of our investigation, we extend an observation by Rogaway and Zhang by further highlighting the close relationship between online ciphers and tweakable blockciphers with variable-length tweaks.

Abstract: Data security is a major concern in cloud computing. It must satisfy three goals of security in computing—integrity, confidentiality, and availability. User or cloud service provider (CSP) can perform operations on cloud data without performing decryption by using homomorphic encryption. Many algorithms are available for homomorphic encryption. These algorithms are generating large size cipher text. In this chapter, small-size cipher text homomorphic encryption algorithm is proposed. This scheme is a modified scheme proposed by Dijk et al. The experimentation is performed on data stored on DynamoDB of Amazon Web Services (AWS) public cloud. All arithmetic computations are performed on low-size encrypted data. Data can be downloaded on users machine as per the requirement and then decrypt it.

Abstract: This chapter introduces the term, data hiding. Hiding data in an honest-looking carrier is not something new—since ancient times humankind tried to find the best means to secure communications, and hiding it was always a commonly used method. Cryptography and steganography are two techniques commonly used to secure and safely transmit digital data. In cryptography we are trying to make our message scrambled and unread; in steganography we are trying to hide the existence of the message by concealing it inside another unsuspicious message. In this chapter, we'll list old techniques invented for encrypting data, like classical ciphers, a transposition cipher, and mechanical cipher machines like the enigma machine used during and before World War II. We will also talk about modern encryption techniques (public and private keys, and hashing) and give examples of each one. In the section on steganography, we begin talking about its types, how older civilizations used it in the past to secure communications, and we will see how these techniques evolved over time, reaching today's digital steganography, which will be our main topic for this book. All these topics will be approached in a practical way, with each technique listed, and a practical example will be given describing in detail how it could be implemented.