Parameterized Verification of Safety Properties in Ad Hoc Network Protocols

We summarize the main results proved in recent work on the parameterized verification of safety properties for ad hoc network protocols. We consider a model in which the communication topology of a network is represented as a graph. Nodes represent states of individual processes. Adjacent nodes represent single-hop neighbors. Processes are finite state automata that communicate via selective broadcast messages. Reception of a broadcast is restricted to single-hop neighbors. For this model we consider a decision problem that can be expressed as the verification of the existence of an initial topology in which the execution of the protocol can lead to a configuration with at least one node in a certain state. The decision problem is parametric both on the size and on the form of the communication topology of the initial configurations. We draw a complete picture of the decidability and complexity boundaries of this problem according to various assumptions on the possible topologies.Comment: In Proceedings PACO 2011, arXiv:1108.145

Analysis of Mozambican websites : how do they protect their users?

Web security is an important approach for most institutions, organizations and individuals which use or provide their services through websites. In this study, a systematic and methodical evaluation of the exposure of web servers and HTTP security headers to attackers that can cause potential harm was tested in 240 Mozambican websites. Vulnerabilities related to HTTP security headers were obtained and the mechanisms which should be taken to reduce the security risks of the services available on the websites are presented