Amal Khalifa

LSBase: A key encapsulation scheme to improve hybrid crypto-systems using DNA steganography

A hybrid cryptosystem is itself a public-key system, whose public and private keys are the same as in the key encapsulation scheme. In this paper, DNA-steganography and cryptography are used together such that the key distribution process is improved without any sacrifice in security. That is, the session key is hidden inside a chosen DNA sequence and hence can be securely exchanged between parties through public channels such as the internet. The proposed steganographic algorithm; called LSBase, uses the codon degeneracy as an efficient way to hide secret information within DNA sequences without actually affecting the type or structure of the protein they code for. Furthermore, the extraction process can be done blindly without any need to the reference sequence.

Dynamic On-Line Allocation of Independent Task onto Heterogeneous Computing Systems to Maximize Load Balancing

Heterogeneous computing (HC) systems use different types of machines, networks, and interfaces to coordinate the execution of various task components which have different computational requirements. This variation in tasks requirements as well as machine capabilities has created a very strong need for developing mapping techniques to decide on which task should be moved to where and when, to optimize some system performance criteria. The existing dynamic heuristics for mapping tasks in HC systems works either on-line (immediate) or in batch mode. In batch mode, tasks are collected into a set that is examined for mapping at prescheduled times called mapping events. On contrast, on-line mode algorithms map a task onto a machine as soon as it arrives at the mapper. In this paper, we propose an on-line mapping algorithm which is called the maximum load balance, or for short the MLB. It tries to minimize the makespan by maximizing the load balancing of the target system. At each task arrival, the MLB algorithm examines all the machines in the HC suite one by one looking for the one that gives the maximum system balance among all possible mappings. In contrast with the opportunistic load balancing (OLB) heuristic; which assigns a task to the machine that becomes ready next, the MLB takes into consideration both the availability of the machine as well as the execution time of the task on that machine.

A Preemptive Version of the Min-Min Heuristic for Dynamically Mapping Meta-Tasks on a Distributed Heterogeneous Environment

Mapping and scheduling of Meta-tasks in distributed heterogeneous computing systems are complex computational problems. They are known to be NP-Complete except under a few special situations. Solving the mapping problem is basically deciding on which task should be moved to where and when, to improve the overall performance. There is a wide variety of approaches to the problem of mapping and scheduling in HC systems that are either static or dynamic. In this paper, we propose a preemptive (migratory) of the Min- min heuristic for mapping a set of independent tasks to machines in a HC suite. The proposed algorithm works dynamically to assign tasks in a batch-mode fashion. In our approach, we revise the decision taken by the Min- min heuristic and adjust its allocation strategy in order to improve machine (processor) utilization and hence achieve better mapping performance by minimizing the makespan.

Quantum secret sharing with identity authentication based on Bell states

Quantum secret sharing techniques allow two parties or more to securely share a key, while the same number of parties or less can efficiently deduce the secret key. In this paper, we propose an authenticated quantum secret sharing protocol, where a quantum dialogue protocol is adopted to authenticate the identity of the parties. The participants simultaneously authenticate the identity of each other based on parts of a prior shared key. Moreover, the whole prior shared key can be reused for deducing the secret data. Although the proposed scheme does not significantly improve the efficiency performance, it is more secure compared to some existing quantum secret sharing scheme due to the identity authentication process. In addition, the proposed scheme can stand against participant attack, man-in-the-middle attack, impersonation attack, Trojan-horse attack as well as information leaks.

DNA Watermarking Using Codon Postfix Technique

DNA watermarking is a data hiding technique that aims to protect the copyright of DNA sequences and ensures the security of private genetic information. In this paper, we proposed a novel DNA watermarking technique that can be used to embed binary bits into real DNA sequences. The proposed technique mutates the codon postfix according to the embedded bit. Our method was tested for a sample set of DNA sequences and the extracted bits showed robustness against mutation. Furthermore, the proposed DNA watermarking method proved to be secured, undetectable, resistance, and preservative to biological functions.

A Blind High-Capacity Wavelet-Based Steganography Technique for Hiding Images into other Images

The flourishing field of Steganography is providing effective techniques to hide data into different types of digital media. In this paper, a novel technique is proposed to hide large a ...

Microarrays Data Analysis for Cancer Disease on a Cluster of Computers

Clustering problem is one of the hottest research fields in microarrays data analysis. In Clustering, a set of observations are assigned into subsets (called clusters) such that observations in the same cluster are similar in some sense. One of the clustering approaches is based on the minimum spanning tree (MST). The MST-based clustering techniques consist of three main phases; MST construction, inconsistent edges identification and clusters identification. The CLUMP algorithm (Clustering through Minimum spanning tree in parallel) is one of the MST-based clustering algorithms, which have been enhanced in the iCLUMP algorithm was improved using the cover tree data structure. This paper presents another improvement called iCLUMP-2 to enhance the edge inconsistency measure employed by both CLUMP and iCLUMP. The performance of the implemented algorithm was tested on a 45 nodes cluster using cancer microarrays data sets. The results showed that the proposed algorithm outperformed both CLUMP and iCLUMP providing better speedup and efficiency. Furthermore the quality of cluster produced by the iCLUMP-2 algorithm is much better that those produced by both CUMP and iCLUMP.

Robust blind image watermarking using DNA-encoding and discrete wavelet transforms

Copyright protection techniques are in great demand due to the widespread illegal copying and communication of digital media. Due to their popularity, various watermarking methods have been proposed lately for digital images. Wavelet-based embedding techniques gained a lot of attention since they provide the perfect balance between imperceptibility and robustness. In this paper, we introduce an algorithm for hiding the complement of a DNA-encoded watermark data into the 3rd level resolution of the wavelet decomposition of a true color image. It applies a quantization operation on the sorted detail coefficients for an enhanced invisible embedding. The extraction process is carried out blindly without the need to refer to the original host image. Experimental results highlighted the excellent invisibility performance of the proposed algorithm. In addition, more than 90% of the embedded watermark survived even under high compression ratios. This outstanding performance continues in comparison with a number of similar methods.