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Soluções SIEM open source: um estudo comparativo
Publication . Vazão, Ana; Santos, Leonel; Piedade, Maria Beatriz; Rabadão, Carlos
Os ataques informáticos estão a aumentar de complexidade e de número de ocorrências, tornando
primordial implementar ferramentas como o Security Information and Event Management (SIEM) para
mitigar os riscos, uma vez que as Organizações dependem cada vez mais dos sistemas informáticos para o
desenvolvimento das suas atividades. O presente trabalho compara várias soluções SIEM open source,
recorrendo à pesquisa bibliográfica e à implementação de vários cenários de testes, com o objetivo de criar um
protótipo e de efetuar a avaliação do mesmo em contexto de produção. A solução escolhida vai ter de ter em
consideração as exigências legais do Regulamento Geral de Proteção de Dados, como é o caso da anonimização
e da pseudoanonimização dos dados sensíveis, o tempo de retenção dos logs e a sua encriptação.
Optimising anti-spam filters with evolutionary algorithms
Publication . Yevseyeva, Iryna; Basto-Fernandes, Vitor; Ruano-Ordás, David; Méndez, José R.
This work is devoted to the problem of optimising scores for anti-spam filters, which is essential for the accuracy of any filter based anti-spam system, and is also one of the biggest challenges in this research area. In particular, this optimisation problem is considered from two different points of view: single and multiobjective problem formulations. Some of existing approaches within both formulations are surveyed, and their advantages and disadvantages are discussed. Two most popular evolutionary multiobjective algorithms and one single objective algorithm are adapted to optimisation of the anti-spam filters' scores and compared on publicly available datasets widely used for benchmarking purposes. This comparison is discussed, and the recommendations for the developers and users of optimising anti-spam filters are provided.
Complexation and DFT studies of lanthanide ions by (2-pyridylmethoxy)homooxacalixarene derivatives
Publication . Marcos, Paula M.; Teixeira, Filipa A.; Segurado, Manuel A.P.; Ascenso, José R.; Bernardino, Raul; Cragg, Peter J.; Michel, Sylvia; Hubscher-Bruder, Véronique; Arnaud-Neu, Françoise
The binding of lanthanide cations by 2-pyridylmethoxy derivatives of p-tert-butyldihomooxacalix[4]arene (1b), in the cone conformation, and p-tert-butylhexahomotrioxacalix[3]arene (2b), in both cone and partial cone conformations, was studied. These properties were assessed by extraction studies of the metal picrates from water into dichloromethane and stability constant measurements in methanol and acetonitrile, using spectrophotometric and microcalorimetric techniques. Proton NMR titrations with La3+ and Yb3+ cations were done in order to get information on the binding sites. Computational methods (density functional theory (DFT) calculations) were also used to complement the NMR data. The p-tert-butylcalix[4]arene analogue (3b) was also studied, and the results of the four ligands were compared. Partial cone-2b is the best extractant for lanthanide ions, showing some preference for the heavy lanthanides. In complexation, all four ligands show the same trend and a high selectivity for Yb3+ (ML, log β ≥ 7). Besides the formation of ML complexes, ML2 species were also obtained. In most cases, these species were corroborated by the proton NMR studies. For partial cone-2b with Pr3+ the complexation process is enthalpically driven, whereas for 3b the formation of the ML2 species with this cation is due to a favourable entropy term. DFT studies indicate that ligand 3b forms the most stable complex with La3+, followed by partial cone-2b.
A Hybrid Application for Real-Time Air Quality Monitoring
Publication . Silva, Jorge; Salgueiro, Pedro; Rato, Luis; Saias, José; Nogueira, Vitor; Lucas, Pedro; Araujo, Filipe; Silva, Catarina; Gil, Paulo; Cardoso, Alberto; Arrais, Joel; Ribeiro, Bernardete; Coutinho, Daniel
With the raising concerns for the environment, interest in monitoring air quality is likely to increase in the near future. However, most data comes from a limited number of government-owned sensors, which can only capture a small fraction of reality. Improving data coverage thus involves reducing the cost of sensors and make data widely available. For this, we will use a very high number of low-cost sensors as the basis for an air quality monitoring platform, capable of collecting, aggregating, storing and displaying data. This platform will use stream-based technologies capable of scaling for large numbers of sensors and users. The resulting NanoSen-AQM platform will provide vast amounts of air quality data to the public, with the aim of improving public health.
CoAP Flow Signatures for the Internet of Things
Publication . Canuto, Luis; Santos, Leonel; Vieira, Leandro; Goncalves, Ramiro; Rabadão, Carlos
The development of technology brought an exponential evolution of IoT networks, and with a number of different devices connected to the Internet, meaning, more IP addresses, traffic and devices susceptible to attacks. These types of networks are characterized by their interoperability and low resources, making it a complex ecosystem and making it difficult to implement management and monitoring measures, leading to a lack of security. Considering the impact that IoT networks have on the market, their protection is essential and, is now one of the themes in constant evolution. With the focus on security, this work aims to characterize a CoAP and CoAPS signatures, through the analysis of a flow in a test scenario and recognize the types of messages of the signature and what is their impact on the network and later creating rules that could help an IDS, in order to save resources and time. When analyzing the flows, it was concluded that it is possible to identify some characteristics of a signature, such as identifying Confirmable and Non-Confirmable messages.