Hierarchical Role-Based Access Control with Homomorphic Encryption for Database as a Service

Database as a service provides services for accessing and managing customers data which provides ease of access, and the cost is less for these services. There is a possibility that the DBaaS service provider may not be trusted, and data may be stored on untrusted server. The access control mechanism can restrict users from unauthorized access, but in cloud environment access control policies are more flexible. However, an attacker can gather sensitive information for a malicious purpose by abusing the privileges as another user and so database security is compromised. The other problems associated with the DBaaS are to manage role hierarchy and secure session management for query transaction in the database. In this paper, a role-based access control for the multitenant database with role hierarchy is proposed. The query is granted with least access privileges, and a session key is used for session management. The proposed work protects data from privilege escalation and SQL injection. It uses the partial homomorphic encryption (Paillier Encryption) for the encrypting the sensitive data. If a query is to perform any operation on sensitive data, then extra permissions are required for accessing sensitive data. Data confidentiality and integrity are achieved using the role-based access control with partial homomorphic encryption.Comment: 11 Pages,4 figures, Proceedings of International Conference on ICT for Sustainable Developmen

Magneto-elastic waves in crystals of magnetic molecules

We study magneto-elastic effects in crystals of magnetic molecules. Coupled equations of motion for spins and sound are derived and the possibility of strong resonant magneto-acoustic coupling is demonstrated. Dispersion laws for interacting linear sound and spin excitations are obtained for bulk and surface acoustic waves. We show that ultrasound can generate inverse population of spin levels. Alternatively, the decay of the inverse population of spin levels can generate ultrasound. Possibility of solitary waves of the magnetization accompanied by the elastic twists is demonstrated.Comment: 8 PR pages, 3 figure

Quantum dynamics of a nanomagnet in a rotating field

Quantum dynamics of a two-state spin system in a rotating magnetic field has been studied. Analytical and numerical results for the transition probability have been obtained along the lines of the Landau-Zener-Stueckelberg theory. The effect of various kinds of noise on the evolution of the system has been analyzed.Comment: 7 pages, 7 figure

Field Dependence of the Electron Spin Relaxation in Quantum Dots

Interaction of the electron spin with local elastic twists due to transverse phonons has been studied. Universal dependence of the spin relaxation rate on the strength and direction of the magnetic field has been obtained in terms of the electron gyromagnetic tensor and macroscopic elastic constants of the solid. The theory contains no unknown parameters and it can be easily tested in experiment. At high magnetic field it provides parameter-free lower bound on the electron spin relaxation in quantum dots.Comment: 4 PR pages, no figure

Principales cambios en la epidemiología de las enfermedades infecciosas en el mundo

ResumenEste trabajo revisa el concepto y el impacto de las nuevas enfermedades infecciosas y las razones para su emergencia; a partir de ahí, describe algunas estrategias para su control. Entre estas medidas se encuentra, en primer lugar. el fortalecimiento de los servicios de salud pública, como la vigilancia epidemiológica y los laboratorios de salud pública, que permitan identificar nuevos brotes y nuevas enfermedades infecciosas. En segundo lugar la difusión rápida de los conocimientos generados, hasta las personas encargadas del control de enfermedades. En tercer lugar, la promoción de la investigación en este campo y la formación de personal especializado. Dentro de la investigación es prioritario el desarrollo de nuevas vacunas, potencialmente útiles también para el control de las enfermedades crónicas, consideradas hasta ahora como no infecciosas (úlceras péptica, coronariopatías, etcétera). Por último, se recomienda un “nuevo abordaje epidemiológico”, que integre los aspectos médicos y sociales de las enfermedades. Este abordaje es además el que permite la necesaria colaboración con los profesionales de otros campos, como la inmunología, la microbiología, la clínica y las ciencias sociales.SummaryThis paper reviews the concept and impact of new infectious diseases and the reasons for their emergence; taking that as a start, it describes some strategies to control them. Among these measures we can find, firstly, the strengthening of public health services, such as epidemiological surveillance and public health laboratories, which allow us to identify new outbreaks and new infectious diseases. Secondly, the quick spread of the knowledge that is generated towards the people who are in charge of the control of diseases, and thirdly, the promotion of research in this field and the training of specialized staff. In the field of research, priority is given to the development of new vaccinations that are potentially useful for the control of chronic diseases which were considered until now as non-infectious (peptic ulcer, coronarypathies, etc.). Finally, a new epidemiological approach which integrates medical and social aspects of diseases is advised. Besides, this approach is what allows the necessary collaboration with professionals from other fields, such as immunology, microbiology, clinics and social sciences

Environmental status of marine plastic pollution in Spain

The excessive use of plastic in our society is causing a massive accumulation, since it is a non-biodegradable product and with still poor recycling rates. This effect can be observed in the seas, which more and more plastic waste are accumulating. The present work is a critical review, based on all currently available literature, that reports environmental status of marine plastic pollution, especially microplastic pollution, in Spain. The three Spanish water areas with the highest presence of plastics are the Alboran Sea, the Gulf of Alicante and the vicinity of Barcelona probably related to fishing and industrial activities and high population densities. With regard to microplastic contamination on beaches in Spain, annual monitoring by the Spanish government shows contamination along the entire coast of the country, with particularly high concentrations in the Canary Islands (between 800 and 8800 particles/m2 in spring). Between 40 and 50% of the particles analyzed were pellets and the main factors postulated for the distribution of these particles are marine currents and the geomorphological characteristics. With regards to biota, ingestion of microplastics by fish has been intensely confirmed and, important differences were observed between the locations of the sampling, being bogues (Boops boops) one of the fish species more studied in Spain. Finally, the work includes a revision of European and Spanish legislation about plastics and marine pollution and some strategies to reduce this kind of contamination in Spain