Abstract: Steganography is an art of hiding the existence of secret information by embedding it in a cover and hence preventing the unauthorized access of confidential information. This paper proposes a novel approach of encrypting the plain text into cipher text and embedding it into a color image. Encryption is done in two stages, during first stage it is encrypted by Ceaser cipher technique and in the second stage it is encrypted based on chaos theory. The cipher text obtained after encryption is embedded using 3, 3, 2 LSB replacement algorithm.

Abstract: Due to widespread applications of 3D vision technology, the research into 3D object protection is primarily important. To maintain confidentiality, encryption of 3D objects is essential. However, the requirements and limitations imposed by 3D objects indicate the impropriety of conventional cryptosystems for 3D object encryption. This suggests the necessity of designing new ciphers. In addition, the study of prior works indicates that the majority of problems encountered with encrypting 3D objects are about point cloud protection, dimensional and spatial stability, and robustness against surface reconstruction attacks. To address these problems, this paper proposes a 3D object encryption scheme, based on a series of random permutations and rotations, which deform the geometry of the point cloud. Since the inverse of a permutation and a rotation matrix is its transpose, the decryption implementation is very efficient. Our statistical analyses show that within the cipher point cloud, points are randomly distributed. Furthermore, the proposed cipher leaks no information regarding the geometric structure of the plain point cloud, and is also highly sensitive to the changes of the plaintext and secret key. The theoretical and experimental analyses demonstrate the security, effectiveness, and robustness of the proposed cipher against surface reconstruction attacks.

Abstract: This paper manifests an innovative approach to transfer sensitive data in an interrupted communication channel using the dyad protection techniques of Cryptography and Steganography. Applying Rotor Caesar cipher on the message followed by 2 bit LSB Steganography helps to conceal the information from the intruder. This Steganography strategy is achieved by using Python Image library along with OpenCV framework.

Abstract: The idea behind this paper describes a modality about secret interface over the globalization of the communication over the world. To accomplish this phenomenon, two varieties of security mechanism, cryptography and steganography is being applied. At the former stage, encryption is being provided to secret plain text using Vernam cipher (One-Time Pad) transposition technique, since Vernam cipher show good performance metrics in terms of less CPU running time, file size same after encryption and strong avalanche effect compare with all transposition cipher. And at the later stage, it transform cipher text into bytes and divides each byte into pairs of bits and assigns the decimal values to each pairs, which is known as master variable, master variable value range will be vary between 0 to 3. Depending upon the master patchy value, add that cipher text in the career image at Least Significant Bit (LSB) 6th and 7th bit location or 7th and 8th bit location or 7th and 6th or 8th and 7th bit location. Which shows the embedding location dynamicity of the algorithm depends upon dynamically changed master variable value. After completion of embedding and sending the stego image to the receiver side, retrieving process of the cipher text from the said locations will be done. And then decryption process to get the secret plain text back will be performed using the Vernam cipher transposition algorithms. In this we provide robust image steganography. Performance analysis observed using MSE and PSNR value.

Abstract: The Vernam cipher, or one-time pad, plays an important role in cryptography because it is perfectly secure. In this cipher a key is a sequence of equiprobable independently generated symbols. We show that under small disturbance of these properties the obtained cipher is close to the Vernam cipher in the case where the enciphered plaintext and the key are generated by stationary ergodic sources.

Abstract: Secured communication of information is important across the globe. Cryptography is one of the methods to attain security of information. The Hill cipher (HC) is one of the famous and known symmetric encryption algorithm based on linear matrix transformation. Hill Cipher has several advantages such as masquerading letter frequencies of the plaintext and high throughput. Despite the ease and speed of the Hill Cipher, the original Hill Cipher is no longer used due to the vulnerability against known plaintext-ciphertext attack. So to enhance security of Hill cipher various methods are proposed by different researchers. This paper aims to present review of various techniques used for Hill Cipher modification to improve performance of Hill Cipher in data security.

Abstract: Objective: For the purpose of Data Communication Steganography is a technique which is combination of both the science and art by which we may hide information inside other covered media. Method: Here we use 3-layers steganographic data encryption, in the first stage data are encoded based upon DNA-Sequence and then the stego-key is added with individual byte then the byte streams are encoded within the image. First encrypt the data is more secure than encoding the raw data and authentication values which provide access only to authorized persons. Finding: Only Steganography is not enough secure for the present scenario. Simple Steganography is very much vulnerable in front of attack, but if we apply some encryption on the data itself and then use Steganography then that will be more secure than the use raw data in Steganography. Application: It will cover all the fields where we need Data Security and it covers a zone of data security where we need to hide the existence of data.

Abstract: Encoding a message in plain text is an ancient art. Using null cipher NC is a great challenge because it requires extensive human efforts and intelligence. In this study, we propose a mechanism which can detect the existence of NC steganography in text without human involvement. We propose a statistical approach based on finding the probability of a ST to generate meaningful words and average word length. A threshhold value THV is defined to distinguish the normal data from unusual statistical data. On the basis of the probability and AWL each ST is assigned a risk factor value. Texts exceeding THV will be marked as infected and the remaining as clean text.

Abstract: To add multiple layers of security our present work proposes a method for integrating together cryptography and Steganography for secure communication using an image file. We have used here combination of cryptography and steganography that can hide a text in an image in such a way so as to prevent any possible suspicion of having a hidden text, after RSA cipher. It offers privacy and high security through the communication channel.

Abstract: Security of information plays a vital role in data transmission. For this purpose steganography and cryptography is plays a major role. Steganography embed a text into cover image and cryptography convert plain text into the cipher text vice versa. There are many algorithms that has been proposed for steganography and cryptography for safe transmission of the data. But intruder sometimes identify the secret message from the stegano image. In the proposed system we apply BSS technique on secret message after to convert the cipher text using RSA algorithm. The cipher text is embedded into cover image using LSB technique, it generates stegano image.

Abstract: The Dhall-Pal Cipher (DPC) is a 128-bit block cipher with a 128-bit key introduced by Dhall and Pal in 2010. It is based on the substitution-permutation network (SPN) structure, and has elements in common with the Advanced Encryption Standard (AES). The most significant differences between the DPC and the AES occur in the linear transformation stage, some components of which are key-dependent in the DPC. In this paper we identify a large set of weak keys for the DPC, and we describe practical attacks enabled by these weak keys. We first present fast distinguishing attacks that succeed for approximately 2124 out of the 2128 keys. We then describe two plaintext-recovery attacks that succeed for 2120 keys. One of these plaintext-recovery attacks can decrypt any ciphertext using only 211 encryptions on average.

Abstract: Objectives: Computer security is all about the study of cyber attacks with a view to defend against them. Cryptography is considered to be a class of science by using the special art of transforming information in a protected way such that it can overcome the attacks. There is an immense requirement of strong cryptographic algorithms in order to withstand against the various attacks. Methods: The Kerchoff''s Principle states that the encryption and decryption algorithms are always available to anyone. The security of the cipher against any sort of attack should be depends only on the secrecy of the key. There comes the play of cryptanalysis. It is art of breaking the keys by identifying the vulnerabilities existing in the systems. This paper deals with the classical encryption schemes and their cryptanalysis. The cryptanalysis for various encryption schemes differs a lot. Various cryptanalysis like statistical analysis, frequency analysis, trial and error (brute force) are carried out in this work. Findings: The classical encryption schemes such as caesar cipher, shift cipher, vigenere cipher, affine cipher and hill cipher are discussed in the paper. A detailed analysis about the security of the above mentioned ciphers are explored. Among the ciphers it is identified that if the key varies for each plaintext to be encrypted provides added security. But the worst is the management of the huge key space. A modified algorithm is proposed which can provide a better security using simple computations. In this approach lots of keys are used but generated from a single key by using simple shift and EXOR operation. In the main stream only one key need to be exchanged between the communication entities and for that exchange we can make use of the public key cryptosystem. Application: Cryptography is considered to be an ineluctable field in era of communication. Cryptographic algorithms acts as an underpinning for lots of applications such as Anonymous Remailers, Digital Signatures, Secured Money transactions etc.

Abstract: Caesar cipher is an ancient, elementary method of encrypting plain text message to protect it from adversaries. However, with the advent of powerful computers there is a need for increasing the complexity of such algorithms. In this paper, we contribute in the area of classical cryptography by providing a modified approach and expanded version for Caesar cipher using knowledge of mathematics and computer science. To increase the strength of this classical encryption technique we use the concepts of affine ciphers, transposition ciphers and randomized substitution techniques to create a cipher text which is nearly impossible to decode. We also increase the domain of characters which Caesar cipher Algorithm can encrypt by including all ASCII and extended ASCII characters in addition to alphabets. A complex key generation technique which generates two keys from a single key is used to provide enhanced security. We aim to propose a modified version of Caesar cipher substitution technique which can overcome all the limitations faced by classical Caesar Cipher.