Formal modeling and analysis of a narrow bandwidth protocol for establishing and terminating connections

International audienceThe paper presents a formal modeling and analysis of a protocol for narrow bandwidth channels of service connection establishment and termination. The protocol is characterized by state traces and formally verified by a theorem proving system PVS. Relevant properties are specified and verified in terms of inductive principles. The effectiveness of the proposed method is evidenced by the elaborate analysis which unveils a subtle bug in the initial protocol implementation. The approach is scalable for an arbitrary number of agents

Algoritmos de compresión paralela

El objetivo planteado inicialmente fue analizar la viabilidad de distribuir un compresor de datos en una red de procesadores. Además de elegir el algoritmo a implementar y definir alternativas de distribución debíamos seleccionar un lenguaje y un sistema operativo que soporten las herramientas de multiprocesamiento necesarias para la implementación de las versiones distribuidas. Nuestro primer paso fué realizar la implementación de dos compresores de datos basados en el mismo algortimo, uno distribuido y otro lineal, y analizar ventajas y desventajas entre ambas implementaciones. El algoritmo de compresión en el que basamos las implementaciones fue el algoritmo de Huffman semiestático (ver Apéndice C2). Básicamente por ser un estándar de compresión de datos ampliamente divulgado, simple, efectivo, y con una importante base teórica. Todas las implementaciones fueron realizadas utilizando el lenguaje de programación C, aumentado, en los casos en que fue necesario, con librerías correspondientes a las distintas herramientas.Tesis digitalizada en SEDICI gracias a la colaboración de la Biblioteca de la Facultad de Informática.Facultad de Ciencias Exacta

Algoritmos de compresión paralela

El objetivo planteado inicialmente fue analizar la viabilidad de distribuir un compresor de datos en una red de procesadores. Además de elegir el algoritmo a implementar y definir alternativas de distribución debíamos seleccionar un lenguaje y un sistema operativo que soporten las herramientas de multiprocesamiento necesarias para la implementación de las versiones distribuidas. Nuestro primer paso fué realizar la implementación de dos compresores de datos basados en el mismo algortimo, uno distribuido y otro lineal, y analizar ventajas y desventajas entre ambas implementaciones. El algoritmo de compresión en el que basamos las implementaciones fue el algoritmo de Huffman semiestático (ver Apéndice C2). Básicamente por ser un estándar de compresión de datos ampliamente divulgado, simple, efectivo, y con una importante base teórica. Todas las implementaciones fueron realizadas utilizando el lenguaje de programación C, aumentado, en los casos en que fue necesario, con librerías correspondientes a las distintas herramientas.Tesis digitalizada en SEDICI gracias a la colaboración de la Biblioteca de la Facultad de Informática.Facultad de Ciencias Exacta

A method for securing online community service: A study of selected Western Australian councils

Since the Internet was made publicly accessible, it has become increasingly popular and its deployment has been broad and global thereby facilitating a range of available online services such as Electronic Mail (email), news or bulletins, Internet Relay Chat (IRC) and World Wide Web (WWW). Progressively, other online services such as telephony, video conference, video on demand, Interactive Television (ITV) and Geographic Information System (GIS) have been integrated with the Internet and become publicly available. Presently, Internet broadband communication services incorporating both wired and wireless network technologies has seen the emergence of the concept of a digital community which has been growing and expanding rapidly around the world. Internet and the ever expanding online services to the wider digital community has raised the issue of security of these services during usage. Most local councils throughout Western Australia have resorted to delivering online services such as library, online payments and email accessibility. The provision and usage of these services have inherent security risks. Consequently, this study investigated the concept of a secure digital community in the secure provision and usage of these online services in selected local councils in Western Australia (WA). After an extensive review of existing literature, information security frameworks were derived from the adaptation of various resources, such as the OSSTMM 2.2 Section C: Internet Technology Security benchmark which was used as the main template. In addition, this template was enhanced into a framework model by incorporating other benchmarks such as NIST, CIS, ISSAF as well as other sources of information. These included information security related books, related ICT network and security websites such as CERT, CheckPoint, Cisco, GFI, Juniper, MS, NESSUS and NMAP together with journals and personal interviews. The proposed information security frameworks were developed to enhance the level of security strength of the email and online web systems as well as to increase the level of confidence in the system security within the selected local councils in WA. All the investigative studies were based upon the available selected local councils’ data and the associated analyses of the results as obtained from the testing software. In addition, the interpretive multiple-case study principles were used during the investigation to achieve or fulfil the purpose of this study. The findings from this study were then abstracted for use in a framework and made available for use as a model for possible adaptation and implementation to other similarly structured councils or organisations. As a result, the study confirmed that the proposed information security frameworks have the capability and potential to improve the level of security strength. In addition, the level of satisfaction and confidence of council staff of the selected local councils in WA in the system security would also be increased due to the application of these frameworks. Although these information security frameworks may be recommended as practical and supporting tools for local councils, the findings from this study were specific only to the selected local councils used in this study. Further research using other councils, may be necessary in order for the information security frameworks to be adopted within a wider range of councils or organisations in WA or elsewhere