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Steganographic techniques are used to transmit secret information using a carrier file without visibility during communication. In this paper, we proposed an improved RGB image steganographic technique for secured communication between two authorized parties. This technique embeds the information within 2nd to 8th bit position of blue (B) or green (G) component or both of a pixel throughout the blue...
A novel method for embedding a covert message in cover audio for secure communication is proposed. The covert message to be embedded can be of any format. In this process, two cover audio files are taken and difference of the amplitude values is calculated. These differences are then classified into number of ranges and are substituted with a new value to embed the secret message. The embedded secret...
Cipher index is a well established technology for improving query efficiency. However, the existing index schemes have defect of lowness in query hit rate which leads to Internet crowdedness. It is the key for this problem to reduce the redundant tuples in query results. A synthetical cipher index technology to eliminate redundant tuples is presented through considering numeric data and character...
Various cryptographic puzzle schemes are proposed as a defense mechanism against denial of service attack. But, all these puzzle schemes face a dilemma when there is a large disparity between the computational power of attackers and legitimate clients: increasing the difficulty of puzzles might unnecessarily restrict legitimate clients too much, and lower difficulty puzzles cannot sufficiently block...
The spread of worldwide networks and the technological trend are feeding the progress of network and distributed computing in different directions (grid, cloud, autonomic, ubiquitous, pervasive, volunteer, etc). With regard to information, great amount of data widely (geographically) spread over the network require adequate management, to ensure availability for authorized users only, confidentiality...
Data De-duplication has become a commodity component in data-intensive storage systems. But compared with other traditional storage paradigms, de-duplication system achieves elimination of data duplications or redundancies at the cost of bringing several additional layers or function components into the I/O path, and these additional components are either CPU-intensive or I/O intensive, largely hindering...
Audit logs are very important part of any secure system and should be highly considered. The content of them which is past events is so sensitive and poses a threat to privacy and information security, so should be protected against any illegal reading and modification. The best way to do this is encryption. Important challenges in an encrypted audit log are speed of log and search process, correctness...
This paper presents a pseudo-random shuffling (PRS) method as an enhancement that can be added to many of the block ciphers by exploiting the strict avalanche criterion (SAC) effect. We then analyze and post the result from comprehensive statistical testing for randomness using Diehard battery of tests to show that the shuffling sequence is indeed random. Finally, we include the performance comparison...
The present study investigates the difficulty of solving the mathematical problem, namely DLP (Discrete Logarithm Problem) for ephemeral keys. DLP is the basis for many public key cryptosystems. The ephemeral keys are used in such systems to ensure the security. The DLP defined on a prime field Zp* of random prime is considered in the present study. The most effective method to solve the DLP is the...
Search indices for distributed information are an important building block for many mobile, decentralized applications. However, the network load caused by nodes registering their information in the index can become quite significant especially in mobile networks like vehicular ad-hoc networks (VANETs), where nodes need to register periodically due to their mobility. Our goal in this paper is to encode...
Many basic key distribution schemes specifically tuned to wireless sensor networks have been proposed in the literature. Recently, several researchers have proposed schemes in which they have used group-based deployment models and assumed predeployment knowledge of the expected locations of nodes. They have shown that these schemes achieve better performance than the basic schemes, in terms of connectivity,...
When large XML documents are shared, documents compression and encryption become simultaneously important for efficient and secure access. Existing approaches for compressing and encrypting large XML documents provide a non-queriable intermediate document representation, creating a need to decompress and decrypt the whole document before any access, which simply wastes computing resources (such as...
Predistribution of cryptographic keys is a widely used approach for establishing secure communication between network nodes which are severely resource-constrained. Many proposed key predistribution schemes make the implicit assumption that message contents need not be kept private from nodes other than the intended recipient. Messages in such schemes are not guaranteed to be confidential--they may...
Secret image sharing is a technique to share the secret among n participants. Each participant has meaningless, noise like shares. The secret image is revealed if any k of the shares are gathered. This scheme uses polynomial based (k, n) secret sharing approach proposed by Shamir in 1979. In 2007, Chen et al. proposed a new secret image sharing method that uses quadratic residues. Their scheme restricts...
Based on the hybrid of piecewise linear chaotic map (PWLCM) and Feistel network, a block cipher algorithm with a 128-bit length key is proposed. Within the algorithm, an 8 ?? 8 S-box generated by chaotic map is used to realize the round function F, and PWLCM is employed to determine the input of the S-boxes. The algorithm operates on 32-bit plaintext blocks through 16 rounds computing. The experiment...
Security is a big challenge when wireless sensor networks are deployed in a hostile environment. Due to the computational and storage overheads, traditional asymmetric cryptographic protocols are not suitable for the resource-constrained wireless sensor nodes. Several key pre-distribution schemes have been proposed in literature to establish pairwise key between sensor nodes, but most of which only...
Social networking sites, such as MySpace, Facebook and Flickr, are gaining more and more popularity among Internet users. As users are enjoying this new style of networking, privacy concerns are also attracting increasing public attention due to reports about privacy breaches on social networking sites. We propose FaceCloak, an architecture that protects user privacy on a social networking site by...
The optimal information rate of a graph (based access structure) is the best achievable information rate of any PSSS realizing it, which has been studied in a large number of articles during the last two decades. However the optimal information rates are only known for certain graphs. It is an open problem to determine the optimal information rates of other graphs. In this paper, we provide optimal...
Encryption is an important approach of ensuring the data security of relational database. However, most existing encryption algorithms, which are regarded as secure, basically can not guarantee that the order in original text still remains in ciphertext, which brings great efficiency problems during the use of encrypted database; on the other hand, those order-preserving encryption algorithms have...
In this paper, we describe new steganalysis methods that can reliably detect distortion due to LSB steganography in images that were originally stored in the JPEG format. Firstly, estimation jpeg compression history, then calculate quality index of the jpeg image. Based stego image and quality index, it can recover the cover image. Comparing stego and cover image, it also enables accurate estmation...
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