Study for Automatically Analysing Non-repudiation

While security issues such as secrecy and authentication have been studied intensively, most interest in non-repudiation protocols has only come in recent years. Non-repudiation services must ensure that when two parties exchange informations over a network, neither one nor the other can deny having participated in this communication. Consequently a non-repudiation protocol has to generate evidences of participation to be used in the case of a dispute. In this paper, we present a description of non-repudiation services, and illustrate them on the Fair Zhou-Gollmann protocol. Then we show how to define non-repudiation properties with the AVISPA tool and explain how they can be automatically verified

Automatic Methods for Analyzing Non-Repudiation Protocols with an Active Intruder

Non-repudiation protocols have an important role in many areas where secured transactions with proofs of participation are necessary. Formal methods are clever and without error, therefore using them for verifying such protocols is crucial. In this purpose, we show how to partially represent non-repudiation as a combination of authentications on the Fair Zhou-Gollmann protocol. After discussing its limits, we define a new method based on the handling of the knowledge of protocol participants. This method is very general and is of natural use, as it consists in adding simple annotations, like for authentication problems. The method is very easy to implement in tools able to handle participants knowledge. We have implemented it in the AVISPA Tool and analyzed the optimistic Cederquist-Corin- Dashti protocol, discovering two unknown attacks. This extension of the AVISPA Tool for handling non-repudiation opens a highway to the specification of many other properties, without any more change in the tool itself

Fercite – feira regional de ciência e tecnologia realizado pela superintêndencia regional de educação de São Mateus: a pedagogia de projetos promovendo a educação científica / Fercite - regional science and technology fair held by the regional superintendence of education of São Mateus: the pedagogy of projects promoting scientific education

Com o intuito de incentivar o protagonismo juvenil, considerando a importância da pedagogia de projetos nas disciplinas que englobam as ciências, por meio da educação científica, valorizando o processo ensino e aprendizagem através da investigação, foi organizado pela equipe da Superintendência de Educação de São Mateus a Fercite – Feira Regional de Ciência e Tecnologia da Superintendência Regional de Educação de São Mateus. A comissão de trabalho foi formada pela equipe gestora e técnicos, denominada de Comissão Organizadora do evento. Através da Feira, buscou-se responder a seguinte pergunta: “É possível trabalhar o currículo por meio da pedagogia de projetos, promovendo a educação científica? Por intermédio da Fercite, os estudantes tiveram a possibilidade de relacionar suas vivencias, com as interfaces de uma educação integrada ao currículo e o contexto na qual estão inseridos, contribuindo para resposta à pergunta em questão. A Feira foi organizada de acordo com as metodologias utilizadas em outros eventos científicos, onde foi decidido por um tema macro contido em edital, quantidade de professores e estudantes por projeto, e o template a ser seguido pelos participantes.

Spatial variability in the icthyoplankton structure of a subtropicalhypersaline lagoon

Abstract The Lagoa de Araruama is a hypersaline ecosystem inhabited by distinct fish species, either permanently or during their reproductive season. Over recent years, some significant environmental changes have been observed in this ecosystem related to the sewage runoff, as salinity decrease (from 64 to 41 psu during the last 40 years) and nutrients increase. As both changes are thought to affect the ichthyoplankton assemblage, the present study aimed to evaluate all the potential relationships between salinity disruption and fish larvae distribution. Ichtyoplankton samples were collected monthly from January 2010 to March 2011 at eight sites in Araruama Lagoon by means of a WP2 plankton net equipped with a flowmeter. During this period, low egg densities were coincident with high salinity regions, suggesting that adults are avoiding to release their eggs under less favorable environmental conditions to the larvae. The uneven distribution of eggs and larvae inside the lagoon, as revealed by both spatial and temporal analyses lead us to suggest that changes in salinity have influenced the reproductive rhythms of those fish species that depend upon the Lagoa de Araruama

Automatically Analysing Non-repudiation with Authentication

Non-repudiation protocols must ensure that when two parties exchange informations over a network, neither one nor the other can deny having participated in this communication. While security issues such as secrecy and authentication have been studied intensively, interest in non-repudiation has only come in recent years and most of the non-repudiation protocol analysis has been done manually. In this paper we present how non-repudiation properties can be modeled as authentication properties; the AVISPA Tool, that supports secrecy and authentication only, is used to automatically analyse the non-repudiation properties of the Fair Zhou-Gollmann protocol

Automatic Methods for Analyzing Non-Repudiation Protocols with an Active Intruder

apport de recherche ISSN 0249-6399 ISRN INRIA/RR--6324--FR+EN