Shuffling Process Research Articles

ReRanz

Recent code reuse attacks are able to circumvent various address space layout randomization (ASLR) techniques by exploiting memory disclosure vulnerabilities. To mitigate sophisticated code reuse attacks, we proposed a light-weight virtual machine, ReRanz, which deployed a novel continuous binary code re-randomization to mitigate memory disclosure oriented attacks. In order to meet security and performance goals, costly code randomization operations were outsourced to a separate process, called the "shuffling process". The shuffling process continuously flushed the old code and replaced it with a fine-grained randomized code variant. ReRanz repeated the process each time an adversary might obtain the information and upload a payload. Our performance evaluation shows that ReRanz Virtual Machine incurs a very low performance overhead. The security evaluation shows that ReRanz successfully protect the Nginx web server against the Blind-ROP attack.

Letter writing as a reflective practice: understanding the shuffling, shifting, and shaping of a researcher identity

This article presents letter writing as a form of arts-based inquiry and reflective practice. The author argues that letter writing can be employed to develop a reflective space for autobiographical reflection. The letter featured here captures and demonstrates the shuffling, shifting, and shaping processes of the author’s researcher identity through letter writing, and is informed by the theoretical underpinnings of reflective practice. It records and investigates the experiences that the author underwent during a compulsory course in the first year of a doctoral program at a North American university. Three interrelated themes are identified in the letter: the researcher identity in crisis, the nature of research, and future researcher identity. It is concluded that letter writing can facilitate the self-evolution, self-introspection, self-awareness, and identity change that emerges with, and through, reflection. Letter writing as a reflective practice offers the benefits of developing self-knowledge, independent thought, critical thinking, and deconstructive understanding of one’s experiences.

Analysis of twinning via automated atomistic post-processing methods

twinning is the most prominent and most studied twin mode in hexagonal close-packed materials. Many works have been devoted to describing its nucleation, growth and interactions with other defects. Despite this, gaps and disagreements remain in the literature regarding some fundamental aspects of the twinning process. A rigorous understanding of the twinning process is imperative because without it higher scale models of plasticity cannot accurately capture deformation in important materials such as Mg, Ti, Zr and Zn. Motivated by this necessity, we have studied twinning using molecular dynamics, focusing on automated processing techniques which can extract mechanistic information generalisable to continuum scale deformation. This demonstrates for the first time the automatic identification of twinning dislocation lines and Burgers vectors, and the elasto-plastic decomposition of the deformation gradient inside and around a twin embryo. These results confirm predictions of most authors regarding the dislocation-based twin growth process, while contradicting others who have argued that twin growth stems from a shuffling process with no dislocation line.

SD-PUF: Spliced Digital Physical Unclonable Function

Digital circuit physical unclonable function (PUF) has been attracting attentions for the merits of resilience to the environmental and operational variations that analog PUFs suffer from. Existing state-of-the-art digital circuit PUFs, however, are either hybrid of analog-digital circuits which are still under the shadow of vulnerability, or impractical for real-world applications. In this paper, we propose a novel highly nonlinear and secure digital PUF (D-PUF) and the spliced version SD-PUF. The fingerprints are extracted from intentionally induced very large-scale integration interconnect randomness during lithography process, as well as a post-silicon shuffling process. Strongly skewed CMOS latches are used to ensure the immunity against environmental and operational variations. Crucially, a highly nonlinear logic network is proposed to effectively spread and augment any subtle interconnect randomness, which also enables strong resilience against machine learning attacks. On top of it, the expandable architecture of the proposed logic network empowers a novel post-silicon shuffle-splice mechanism, where multiple randomly selected D-PUFs are spliced to be one SD-PUF, pushing the statistical security to a much higher level, while significantly reducing the mask cost per PUF device. It also decouples the trustworthy demands enforced to the foundries or other third party manufacturers. Our proposed PUFs demonstrate close to ideal performance in terms of statistical metrics, including 0 intra-Hamming distance. Various state-of-the-art machine learning models show prediction accuracies almost no better than random guesses when attacking to the proposed PUFs. We also mathematically prove the probability of existence of identical SD-PUF pair is significantly lower than that of D-PUF pair, e.g., such probability of an SD-PUF spliced by 30 D-PUFs is ${2.3\times 10^{-22}}$ , which is 19 order magnitude lower than that of D-PUF. Benefited from the proposed shuffle-splice mechanism, the mask cost per SD-PUF is also reduced by ${300\times }$ than that of D-PUF.

A Novel Image Stream Cipher Based On Dynamic Substitution

Recently, many chaos-based stream cipher algorithms have been developed. Traditional chaos stream cipher is based on XORing a generated secure random number sequence based on chaotic maps (e.g. logistic map, Bernoulli Map, Tent Map etc.) with the original image to get the encrypted image, This type of stream cipher seems to be vulnerable to chosen plaintext attacks. This paper introduces a new stream cipher algorithm based on dynamic substitution box. The new algorithm uses one substitution box (S-box) and a chaotic shuffling process. Each byte in the plain image vector is substituted using a different S-box to get the cipher image vector. This algorithm is designed to be invulnerable to chosen plaintext attacks. In addition, this algorithm is more secured compared to conventional stream cipher.

A lévy flight-based shuffled frog-leaping algorithm and its applications for continuous optimization problems

Shuffled frog-leaping algorithm (SFLA), a novel meta-heuristic optimization algorithm inspired by the foraging behavior of frogs, has been widely applied to many areas for combination problems. But it is easy to fall into the local optimum especially for the continuous optimization problems. This paper proposed a novel variant of SFLA for the continuous optimization problems based on the expanded framework (called the lévy flight-based shuffled frog-leaping algorithm, LSFLA). In this new framework, the shuffling process, local search step and global search step are combined according to the exploration and exploitation mechanism. An lévy flight based attractor was adopted for the local search step, which enhance the local search ability of algorithm due to the search of short walking distance and occasionally longer walking distance. An interaction learning rule was used for the global search step, which enhances the exploration ability. In order to test the effectiveness of LSFLA, thirty benchmark functions, six real-world constrained continuous optimization problems and a real-world support vector machine (SVM) parameter optimization problem were compared to the many well-known heuristic methods. The experimental results demonstrate that the performance of our proposed algorithm is better than other algorithms for the continuous optimization problems.

A shuffled multi-swarm micro-migrating birds optimizer for a multi-resource-constrained flexible job shop scheduling problem

Scheduling problems with resource constraints have been a new research trend in recent years. This paper addresses a multi-resource-constrained flexible job shop scheduling problem that is very common in semiconductor manufacturing, precision engineering, and many other modern industries. To address this important problem, a novel algorithm called the shuffled multi-swarm micro-migrating birds optimization (SM2-MBO) algorithm is presented with a two-vector representation. The SM2-MBO forms a number of micro-swarms, each of which performs its own MBO independently. A random shuffle process applied to the entire population is invoked periodically to propagate the good information that is found in some of the micro-swarms. A diverse controlling strategy based on the aging phenomenon of life is proposed to diversify the population. An adaptive search operator based on a problem-specific crossover and a two-vector crossover helps to balance exploitation and exploration. Numerical experiments and comparisons are conducted against the best performing algorithms reported in the literature for the considered problem. The results demonstrate that the proposed SM2-MBO performs significantly better than the existing algorithms in solving the multi-resource-constrained flexible job shop scheduling problem with the makespan criterion. Furthermore, the proposed SM2-MBO can improve 9 out of 10 best known solutions for the benchmark instances in the literature.

An intermediate data placement algorithm for load balancing in Spark computing environment

Since MapReduce became an effective and popular programming framework for parallel data processing, key skew in intermediate data has become one of the important system performance bottlenecks. For solving the load imbalance of bucket containers in the shuffle process of the Spark computing framework, this paper proposes a splitting and combination algorithm for skew intermediate data blocks (SCID), which can improve the load balancing for various reduce tasks. Because the number of keys cannot be counted out until the input data are processed by map tasks, this paper provides a sampling algorithm based on reservoir sampling to detect the distribution of the keys in intermediate data. Contrasting with the original mechanism for bucket data loading, SCID sorts the data clusters of key/value tuples from each map task according to their sizes, and fills them into the relevant buckets orderly. A data cluster will be split once it exceeds the residual volume of the current bucket. After filling this bucket, the remainder cluster will be entered into the next iteration. Through this processing, the total size of data in each bucket is roughly scheduled equally. For each map task, each reduce task should fetch the intermediate results from a specific bucket, the quantity in all buckets for a map task will balance the load of the reduce tasks. We implement SCID in Spark 1.1.0 and evaluate its performance through three widely used benchmarks: Sort, Text Search, and Word Count. Experimental results show that our algorithms can not only achieve higher overall average balancing performance, but also reduce the execution time of a job with varying degrees of data skew.

Critical Stresses for Twinning, Slip, and Transformation in Ti-Based Shape Memory Alloys

We investigate the effect of Nb and Ta contents on the (i) critical resolved shear stress (CRSS) for the β − α″ transformation, (ii) the CRSS for austenite slip, and (iii) the CRSS for twin nucleation in martensite (α″ phase) that govern shape memory and superelasticity in Ti-based alloys. The critical stresses for slip and twinning are achieved with a modified Peierls Nabarro formalism utilizing generalized stacking fault energy and the generalized planar fault energy (GPFE), respectively, obtained from first-principles density functional theory (DFT) calculations. During the calculation of the twinning stress, we show the importance of the shuffling process in stabilizing and lowering the GPFE curve. Similarly, the transformation stress is obtained with heterogeneous martensite nucleation mechanism incorporating the energy barriers associated with the transformation process. Here, we point to the role of dislocations in the shuffling process during the early stage of transformation. We show that the increase of Ta content raises the CRSS more effectively for the case of slip compared to twinning or transformation. The slip stress and twin stress magnitudes increase with an increase in the unstable fault energy $$\left( {\gamma_{\text{us}} } \right)$$ and unstable twinning fault energy $$\left( {\gamma_{\text{ut}} } \right),$$ respectively. In summary, as the Ta composition increases, the difference between martensite/austenite slip resistance and the transformation/twinning stress widens showing the efficacy of Ta alloying additions.

A Pseudonym Management System to Achieve Anonymity in Vehicular Ad Hoc Networks

In this paper we propose a framework for providing anonymity to communicating cars in VANETs. The anonymity is accomplished based on a system of pseudonym generation, distribution, and replenishing. The road side units (RSUs) play a key role in the framework by receiving the originally generated pseudonyms from the trusted authority, and then distributing pseudonym sets to cars while shuffling the sets amongst themselves to maximize anonymity. The pseudonym distribution process among the RSUs and to the vehicles is highly adaptive to accommodate the needs of the vehicles. We develop a distributed optimization algorithm for the shuffling process and a novel mechanism for cars to change their pseudonyms. Experimental evaluations based on ns3 simulations demonstrate the effectiveness of the framework through showing relatively high values of the used metric, namely the anonymity set.

Chimeric transcripts resulting from complex duplications in chromosome Xq28.

Gene fusions have been observed in somatic alterations in cancer and in schizophrenia. However, the underlying mechanism(s) for their formation are poorly understood. We experimentally demonstrated the expression of splicing variants of in silico predicted chimeric genes F8/CSAG1 and BCAP31/TEX28 in two individuals with de novo complex genomic rearrangements of Xq28; F8/CSAG1 includes exonization of an ERVL-MaLR intronic repetitive element. We provide evidence that replicative repair may contribute to exon shuffling processes and diversify the repertoire of expressed transcripts.

The effect of high yttrium solute concentration on the twinning behaviour of magnesium alloys

The deformation behaviour of two single phase binary alloys, Mg–5Y and Mg–10Y, have been examined. In compression, two twin types were observed, the common {101¯2} twin as well as the less common {112¯1} extension twin. It is shown that the {112¯1} twin is much less sensitive to solute concentration than the {101¯2} twin, and it is suggested that the simple atomic shuffle of the {112¯1} twin reduces the solute strengthening imparted by Y additions. The common {101¯2} twin showed significant hardening as a result of alloying with Y. An analysis of solute behaviour has indicated that of the four chemical parameters investigated, i.e. atomic size, shear modulus, electronegativity and solute distribution, it appears to be the larger atomic radius of Y compared to Mg that increases the stress required to activate the {101¯2} twin. It is suggested that the large atomic radius inhibits the atomic shuffling process which accompanies the twinning shear in this twin type.

Shuffling Expressions with MapReduce Arrangements and the Role of Binary Path Symmetry

intention of MapReduce Sets for Shuffling expressions analysis has to suggest criteria how Shuffling expressions in Shuffling data can be defined in a meaningful way and how they should be compared. Similitude based MapReduce Sets for Shuffling Expression Analysis and MapReduce Sets for Assignment is expected to adhere to fundamental principles of the scientific Shuffling process that are expressiveness of Shuffling models and reproducibility of their Shuffling inference. Shuffling expressions are assumed to be elements of a Shuffling expression space or Conjecture class and Shuffling data provide which of these Shuffling expressions should be used to interpret the Shuffling data. An inference Shuffling algorithm constructs the mapping between Shuffling data and Shuffling expressions, in particular by a Shuffling cost minimization process. Fluctuations in the Shuffling data often limit the Shuffling precision, which we can achieve to uniquely identify a single Shuffling expression as interpretation of the Shuffling data. We advocate an information theoretic perspective on Shuffling expression analysis to resolve this dilemma where the tradeoff between Shuffling informativeness of statistical inference Shuffling and their Shuffling stability is mirrored in the information- theoretic Shuffling optimum of high Shuffling information rate and zero communication expression error. The inference Shuffling algorithm is considered as an outlier object Shuffling path, which naturally limits the resolution of the Shuffling expression space given the uncertainty of the Shuffling data. KeywordsShuffling expressions, kernel function.

Independent birth of a novel TRIMCyp in Tupaia belangeri with a divergent function from its paralog TRIM5.

The origin of novel genes and their evolutionary fates are long-standing questions in evolutionary biology. These questions become more complicated for genes conserved across various lineages, such as TRIM5, an antiretroviral restriction factor and a retrovirus capsid sensor in immune signaling. TRIM5 has been subjected to numerous pathogenic challenges and undergone dynamic evolution, making it an excellent example for studying gene diversification. Previous studies among several species showed that TRIM5 gained genetic and functional novelty in a lineage-specific manner, either through gene duplication or a cyclophilin A retrotransposing into the TRIM5 locus, creating the gene fusion known as TRIM5-Cyclophilin A (TRIMCyp). To date, the general pattern of TRIM5 across the mammalian lineage remains elusive. In this study, we surveyed 36 mammalian genomes to verify a potentially novel TRIM5 pattern that uniquely seems to have occurred in tree shrews (Tupaia belangeri), and found that both gene duplication and retrotransposition worked jointly to form a specific TRIM5/TRIMCyp cluster not found among other mammals. Evolutionary analyses showed that tree shrew TRIMCyp (tsTRIMCyp) originated independently in comparison with previously reported TRIMCyps and underwent strong positive selection, whereas no signal of positive selection was detected for other tree shrew TRIM5 (tsTRIM5) genes. Functional assay results suggest a functional divergence between tsTRIMCyp and its closest paralog TRIM5-4, likely reflecting different fates under diverse evolutionary forces. These findings present a rare example of novel gene origination resulting from a combination of gene duplication, retrotransposition, and exon shuffling processes, providing a new paradigm to study genetic innovations and evolutionary fates of duplicated genes.

Analysis and improvement of a novel image fusion encryption algorithm based on DNA sequence operation and hyper-chaotic system

Recently, a novel image encryption algorithm based on DNA operation and hyper-chaotic system has been proposed by Zhang et al. The encryption algorithm first shuffles the image pixels using Chen chaotic system. After shuffling process, the proposed encryption algorithm changes the gray levels of the image pixels using DNA operation. In this study, we give out complete break for the proposed cryptosystem using a chosen plaintext attack. Both mathematical proofs and experimental results are presented to support the proposed attacks. Main motivation behind this study was to analyze whether proposed image encryption algorithm is suitable for secure communication or not. Based on the results of our analysis, we also discussed the potential improvements for the algorithm and proposed a modified new encryption algorithm accordingly. Essential elements of designing secure image encryption algorithms and potential application areas are also stated.

A multi-objective shuffled frog leaping algorithm for in-core fuel management optimization

The efficient operation and in-core fuel management of PWRs are of utmost importance. In the present work, a core reload optimization using Shuffled Frog Leaping (SFL) algorithm is addressed and mapped on nuclear fuel loading pattern optimization. SFL is one of the latest meta-heuristic optimization algorithms which is used for solving the discrete optimization problems and inspired from social behavior of frogs. The algorithm initiates the search from an initial population and carries forward to draw out an optimum result. This algorithm employs the use of memetic evolution by exchanging ideas between the members of the population in each local search. The local search of SFL is similar to particle swarm optimization (PSO) and applying shuffling process accomplishes the information exchange between several local searches to obtain an overall optimum result. To evaluate the proposed technique, Shekel’s Foxholes and a VVER-1000 reactor are used as test cases to illustrate performance of SFL. Among numerous neutronic and thermal-hydraulic objectives necessary for a fuel management problem to reach an overall optimum, this paper deals with two neutronic objectives, i.e., maximizing effective multiplication factor and flattening power distribution in the core, to evaluate the capability of applying SFL algorithm for a fuel management problem. The results, convergence rate and reliability of the method are quite promising and show the potential and efficiency of the technique for other optimization applications in the nuclear engineering field.

Library Generation by Gene Shuffling

This unit describes the process of gene shuffling, also known as sexual PCR. Gene shuffling is a facile method for the generation of sequence libraries containing the information from a family of related genes. Essentially, related genes are fragmented by DNase I digestion and reassembled by primer-less PCR. The resulting chimeric genes can then be screened or selected for a desired function.

Securing multimedia colour imagery using multiple high dimensional chaos-based hybrid keys

The rapid exchange of multimedia data over worldwide available internet and shared networks has encouraged its unauthorised access, illegal usage, disruption, alteration. Therefore, it demands efficient methods to provide security to multimedia contents for ensuring authorised access, preventing illegal disruption, alteration, etc. To meet the aforesaid needs, the authors propose an efficient encryption method to secure the multimedia colour imagery. Complex dynamic responses of multiple high-order chaotic systems are utilised to carry out image pixels shuffling and diffusion processes under the control of secret key. The pixels diffusion is done by randomly picking the actual encryption keys out of nine hybridised keys that are extracted from complex sequences of Chen, Rossler and Chua chaotic systems. Eventually, a high encryption effect is turned up in the encrypted multimedia colour images. Moreover, the shuffling and diffusion processes are made plain-image information dependent to resist the potential chosen-plaintext, chosen-ciphertext and known-plaintext attacks. The simulation results validate that the proposed method has great encryption performance and practicableness.

High Efficient Complex Parallelism for Cryptography

Cryptography is an important in security purpose applications. This paper contributes the complex parallelism mechanism to protect the information by using Advanced Encryption Standard (AES) Technique. AES is an encryption algorithm which uses 128 bit as a data and generates a secured data. In Encryption, when cipher key is inserted, the plain text is converted into cipher text by using complex parallelism. Similarly, in decryption, the cipher text is converted into original one by removing a cipher key. The complex parallelism technique involves the process of Substitution Byte, Shift Row, Mix Column and Add Round Key. The above four techniques are used to involve the process of shuffling the message. The complex parallelism is highly secured and the information is not broken by any other intruder.

High Efficient Complex Parallelism for Cryptography

Cryptography is an important in security purpose applications. This paper contributes the complex parallelism mechanism to protect the information by using Advanced Encryption Standard (AES) Technique. AES is an encryption algorithm which uses 128 bit as a data and generates a secured data. In Encryption, when cipher key is inserted, the plain text is converted into cipher text by using complex parallelism. Similarly, in decryption, the cipher text is converted into original one by removing a cipher key. The complex parallelism technique involves the process of Substitution Byte, Shift Row, Mix Column and Add Round Key. The above four techniques are used to involve the process of shuffling the message. The complex parallelism is highly secured and the information is not broken by any other intruder.