Salesian Journal on Information Systems

7

Authors: NASCIMENTO, P. S.; FREITAS, A. E. S.

Data management in environments based on several clouds (cloud-of-clouds) should be dependable and secure. DEPSKY may assure that characteristics through mechanisms as cryptography and data replication, however DEPSKY does not support concurrent writing, a desirable functionality for many applications. This paper presents the development and a performance analysis of a lock algorithmfor DEPSKY storage system. The paper also presents validation test and performance test of the algorithm. Such protocol allows concurrent writing, through a low contention lock mechanism that uses lock filesfi to dene who is allowed to write in a data unit.

9

Authors: ALBARELO, P. C.; MARTINI, G.; BARBOSA, J. L. V.

Professionals are constantly seeking qualification and consequently increasing their knowledge in their area of expertise. Thus, it is interesting to develop a computer system that knows its users and their work history. Using this information, even in the case of professional role change, the system could allow the renewed authorization for activities, based on previously authorized use. This article proposes a model for user access control that is embedded in a context-aware environment. The model applies the concept of trails to manage access control, recording activities usage in contexts and applying this history as a criterion to grant new accesses. Despite the fact that previous related research works consider contexts, none of them uses the concept of trails. Hence, the main contribution of this work is the use of a new access control criterion, namely, the history of previous accesses (trails). A prototype was implemented and applied in an evaluation based on scenarios. The results demonstrate the feasibility of the proposal, allowing for access control systems to use an alternative way to support access rights.

12

Authors: GARCIA, C. M.; ABILIO, R.; MALHEIROS, N.

This case study aims to analyze the integration's approaches and technologies among information systems and services in an academic environment. It has been done a study on the integration history in the Federal University of Lavras. The data had been gathered via questionnaires and documentation analysis. In this analysis, 4 distinct phases were specified. Besides, the advantages and disadvantages of each phase were discussed. The main contribution of this work is the analysis of different integration approaches among information systems and other services.