Omani Students’ Application of the Second Standard for Technology Coaches in Internship Program

The aim of this study was to investigate the extent to which Omani students apply In- ternational Society for Technology in Education (ISTE) second standard for technology coaches and its relation with gender, training institution type, student’s specialization, GPA and cohort. A questionnaire of twenty three items to measure the components of the second standard was derived from these components and used. A sample of 171 students was used to collect data. Onsite supervisors were used to evaluate students’ application of the second standard. The re- sults indicate that the overall performance of the students reflects a reasonable and acceptable performance but does not reach the target and desirable performance. Statistical analysis shows no significant differences due to gender, and cohort but there were significant differences due to students’ specialization, institution type and students’ GPA. The study concludes with some recommendations to improve the weak components and revise the procedures and processes of the internship progra

Mind the Gap - A Closer Look at the Security of Block Ciphers against Differential Cryptanalysis

Resistance against differential cryptanalysis is an important design criteria for any modern block cipher and most designs rely on finding some upper bound on probability of single differential characteristics. However, already at EUROCRYPT'91, Lai et al. comprehended that differential cryptanalysis rather uses differentials instead of single characteristics. In this paper, we consider exactly the gap between these two approaches and investigate this gap in the context of recent lightweight cryptographic primitives. This shows that for many recent designs like Midori, Skinny or Sparx one has to be careful as bounds from counting the number of active S-boxes only give an inaccurate evaluation of the best differential distinguishers. For several designs we found new differential distinguishers and show how this gap evolves. We found an 8-round differential distinguisher for Skinny-64 with a probability of 2−56.932−56.93, while the best single characteristic only suggests a probability of 2−722−72. Our approach is integrated into publicly available tools and can easily be used when developing new cryptographic primitives. Moreover, as differential cryptanalysis is critically dependent on the distribution over the keys for the probability of differentials, we provide experiments for some of these new differentials found, in order to confirm that our estimates for the probability are correct. While for Skinny-64 the distribution over the keys follows a Poisson distribution, as one would expect, we noticed that Speck-64 follows a bimodal distribution, and the distribution of Midori-64 suggests a large class of weak keys

Bison: Instantiating the Whitened Swap-Or-Not Construction

International audienceWe give the first practical instance-bison-of the Whitened Swap-Or-Not construction. After clarifying inherent limitations of the construction, we point out that this way of building block ciphers allows easy and very strong arguments against differential attacks

Optimal Forgeries Against Polynomial-Based MACs and GCM

Polynomial-based authentication algorithms, such as GCM and Poly1305, have seen widespread adoption in practice. Due to their importance, a significant amount of attention has been given to understanding and improving both proofs and attacks against such schemes. At EUROCRYPT 2005, Bernstein published the best known analysis of the schemes when instantiated with PRPs, thereby establishing the most lenient limits on the amount of data the schemes can process per key. A long line of work, initiated by Handschuh and Preneel at CRYPTO 2008, finds the best known attacks, advancing our understanding of the fragility of the schemes. Yet surprisingly, no known attacks perform as well as the predicted worst-case attacks allowed by Bernstein\u27s analysis, nor has there been any advancement in proofs improving Bernstein\u27s bounds, and the gap between attacks and analysis is significant. We settle the issue by finding a novel attack against polynomial-based authentication algorithms using PRPs, and combine it with new analysis, to show that Bernstein\u27s bound, and our attacks, are optimal

Social Networks Sites: Usage and Effects

The aim of this paper is to explore the students’ use of social networks sites (SNSs) and its effects on students’ achievement. A questionnaire using a Liker type scale was distributed to a sample of 120 undergraduate students who participated in the study. The results show that students use SNSs for social matters more than for academic purposes. In this regard, there is no significant difference in the use of social network sites between female and male students. Students with smart mobile phones use SNSs more than those with normal mobiles. Facebook was the most used site. There is no significant difference in students’ use of SNSs due to students GPA. More than fifty percent of sampled students spent two hours or more per day on SNSs. The study concludes with some recommendations.

Prevalence of Depression in Elderly People Living With HIV: A Systematic Review and Meta-analysis

We conducted a systematic review and meta-analysis to determine the prevalence of depression among elderly people living with HIV. We searched electronic databases and included 12 observational studies that reported on depression among people who were 50 years of age or older and had HIV. The studies were mostly hospital-based and from Western and African countries. They included a total of 5868 older people with HIV, of whom 1667 had depression. Pooled prevalence of depression was 28% with heterogeneity of 95.2%. Prevalence ranged from 14.5% in the Netherlands to 42.4% in South Africa. Although there was asymmetry in the funnel plot, the Egger\u27s test showed no significant publication bias. Our meta-analysis found a high burden of depression among older people with HIV. Comprehensive health services addressing psychosocial needs and interventions to prevent and treat depression are needed, especially in community settings. Healthcare providers and policymakers should address the prevalence of depression in such communities