An Implementation of Role-Base Trust Management Extended with Weights on Mobile Devices

AbstractThis paper describes the implementation of a library for the management and evaluation of Role-based Trust Management (RT) credentials and policies written in RTML, also extended with weights, in mobile devices. In particular, it describes the implementation of the library in J2ME. It is worth noticing, that RTML credentials are XML-like documents and thus the capability of porting these features on mobile devices makes the overall framework very interoperable with other RT frameworks (as for GRID systems). As policy language, we use actually a variant of RTML, whose policies are added with weights and are able to express quantitative experience-based notions of trust. It allow also to encode certain reputation and recommendation models. The obtained results show how the implementation on mobile devices is feasible and the running time acceptable for several applications

Secure Cloud Storage: A Framework for Data Protection as a Service in the Multi-cloud Environment

This paper introduces Secure Cloud Storage (SCS), a framework for Data Protection as a Service (DPaaS) to cloud computing users. Compared to the existing Data Encryption as a Service (DEaaS) such as those provided by Amazon and Google, DPaaS provides more flexibility to protect data in the cloud. In addition to supporting the basic data encryption capability as DEaaS does, DPaaS allows users to define fine-grained access control policies to protect their data. Once data is put under an access control policy, it is automatically encrypted and only if the policy is satisfied, the data could be decrypted and accessed by either the data owner or anyone else specified in the policy. The key idea of the SCS framework is to separate data management from security management in addition to defining a full cycle of data security automation from encryption to decryption. As a proof-of-concept for the design, we implemented a prototype of the SCS framework that works with both BT Cloud Compute platform and Amazon EC2. Experiments on the prototype have proved the efficiency of the SCS framework

Un aspetto della “Rangordnung” altoimperiale: le carriere dei centuriones, il rango equestre e le tres militiae

The present state of the art on legionary centurions owes its core to the works of Brian Dobson. This paper will show how and why his results need a close scrutiny in order to correct factual errors and faulty assumptions about the centurions and their careers

Antagonism between salicylate and the cAMP signal controls yeast cell survival and growth recovery from quiescence

Aspirin and its main metabolite salicylate are promising molecules in preventing cancer and metabolic diseases. S. cerevisiae cells have been used to study some of their effects: (i) salicylate induces the reversible inhibition of both glucose transport and the biosyntheses of glucose-derived sugar phosphates, (ii) Aspirin/salicylate causes apoptosis associated with superoxide radical accumulation or early cell necrosis in MnSOD-deficient cells growing in ethanol or in glucose, respectively. So, treatment with (acetyl)-salicylic acid can alter the yeast metabolism and is associated with cell death. We describe here the dramatic effects of salicylate on cellular control of the exit from a quiescence state. The growth recovery of long-term stationary phase cells was strongly inhibited in the presence of salicylate, to a degree proportional to the drug concentration. At high salicylate concentration, growth reactivation was completely repressed and associated with a dramatic loss of cell viability. Strikingly, both of these phenotypes were fully suppressed by increasing the cAMP signal without any variation of the exponential growth rate. Upon nutrient exhaustion, salicylate induced a premature lethal cell cycle arrest in the budded-G2/M phase that cannot be suppressed by PKA activation. We discuss how the dramatic antagonism between cAMP and salicylate could be conserved and impinge common targets in yeast and humans. Targeting quiescence of cancer cells with stem-like properties and their growth recovery from dormancy are major challenges in cancer therapy. If mechanisms underlying cAMP-salicylate antagonism will be defined in our model, this might have significant therapeutic implications

Context-Aware Analysis of Data Sharing Agreements

A Data Sharing Agreement is an agreement among contracting parties regulating how they share data under certain contextual conditions. Upon the definition phase, where the parties negotiate the respective authorizations on data covered by the agreement, the resulting policy may be analysed in order to identify possible conflicts or incompatibilities among authorizations clauses. In this paper, we propose a formal framework for Data Sharing Agreement analysis. Our proposal is built on a process algebra formalism dealing with contextual data, encoded into the Maude engine to make it executable. The effectiveness of the analysis is shown through a sensitive data sharing test bed. Furthermore, we present an implementation of the analyser exposed as a Web Service built on top of Maude. The Web Service technology allows the modularity of the whole architecture with respect to the analysis tool