Data security and trustworthiness in online public services: An assessment of Portuguese institutions

Providing public services through the internet is an effective approach towards an encompassing number of citizens being covered by them and for cost reduction. However, the fast development of this area has fostered discussion and legislation regarding information security and trustworthiness. In addition to security mechanisms for data processed and stored internally, service providers must ensure that data exchanged between their servers and citizens are not intercepted or modified when traversing heterogeneous and uncontrolled networks. Moreover, such institutions should provide means enabling the citizen to verify the authenticity of the services offered. In this way, the present work provides a comprehensive overview regarding the security posture of Portuguese public institutions in their online services. It consists of non-invasive robustness evaluation of the deployed solutions for end-to-end data encryption and the correct use of digital certificates. As a result, we provide some recommendations aiming to enhance the current panorama in the majority of the 111 online services considered in this study.This paper is a result of the project SmartEGOV: Harnessing EGOV for Smart Governance (Foundations, Methods, Tools) NORTE-01-0145-FEDER-000037, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (EFDR)

Causality tracking in dynamic distributed systems

Tese de Doutoramento - Área do Conhecimento Tecnologias da ProgramaçãoA causalidade desempenha um papel central no tratamento de problemas importantes de sistemas distribuídos, tais como na replicação de dados, na análise de execuções, na comunicação em grupo e na determinação de estados globais. Por forma a ser útil, a causalidade precisa de ser concretizada em mecanismos que procedam ao seu registo. Os mecanismos existentes, tais como os vectores versão e os relógios vectoriais, assumem a existência de um mapeamento entre identificadores globalmente únicos e contadores inteiros. Num sistema em que é conhecido o número de entidades, é possível pré-configurar estes identificadores por forma a ocuparem posições distintas num vector ou serem-lhe atribuídos nomes distintos. A gestão destas identidades é bem mais problemática em ambientes dinâmicos, com grande número de entidades e onde estas são permanentemente criadas e destruídas. Esta situação é agravada na presença de partições de rede. As soluções actuais para o registo de causalidade não se revelam apropriadas a estes cenários, cada vez mais relevantes. Esta tese apresenta novos mecanismos de registo de causalidade que têm a propriedade de poder ser usados em cenários com um número dinâmico de entidades. Estes mecanismos permitem a criação descentralizada de entidades (processos ou réplicas) sem requerer identificadores globais ou coordenação global para a sua geração. Estes mecanismos apresentam codificações com tamanho variável, o que permite uma adaptação automática ao número de entidades em jogo, crescendo e colapsando de acordo com as necessidades.Causality plays a central role as a building block in solving important problems in distributed systems, such as replication, debugging, group communication and global snapshots. To be useful, causality must be realised by actual mechanisms that can track it and encode it. Existing causality tracking mechanisms, such as vector clocks and version vectors, rely on mappings from globally unique identifiers to integer counters. In a system with a well known set of entities these identifiers can be pre-configured and given distinct positions in a vector or distinct names in a mapping. Identity management is more problematic in dynamic systems, with a large and highly variable number of entities, being worsened when network partitions occur. Present solutions for causality tracking are not appropriate to these increasingly common scenarios. This thesis introduces novel causality tracking mechanisms that can be used in scenarios with a dynamic number of entities. These allow completely decentralised creation of entities (processes or replicas) with no need for global identifiers or global coordination. These mechanisms have a variable size representation that adapts automatically to the number of entities, growing or shrinking appropriately

Interval tree clocks: a logical clock for dynamic systems

Lecture Notes in Computer Science 5401, 2008Causality tracking mechanisms, such as vector clocks and version vectors, rely on mappings from globally unique identifiers to integer counters. In a system with a well known set of entities these ids can be preconfigured and given distinct positions in a vector or distinct names in a mapping. Id management is more problematic in dynamic systems, with large and highly variable number of entities, being worsened when network partitions occur. Present solutions for causality tracking are not appropriate to these increasingly common scenarios. In this paper we introduce Interval Tree Clocks, a novel causality tracking mechanism that can be used in scenarios with a dynamic number of entities, allowing a completely decentralized creation of processes/replicas without need for global identifiers or global coordination. The mechanism has a variable size representation that adapts automatically to the number of existing entities, growing or shrinking appropriately. The representation is so compact that the mechanism can even be considered for scenarios with a fixed number of entities, which makes it a general substitute for vector clocks and version vectors

Version stamps-decentralized version vectors

Version vectors and their variants play a central role in update tracking in optimistic distributed systems. Existing mechanisms for a variable number of participants use a mapping from identities to integers, and rely on some form of global configuration or distributed naming protocol to assign unique identifiers to each participant. These approaches are incompatible with replica creation under arbitrary partitions, a typical mode of operation in mobile or poorly connected environments. We present an update tracking mechanism that overcomes this limitation; it departs from the traditional mapping and avoids the use of integer counters, while providing all the functionality of version vectors in what concerns version tracking

Promoting entrepreneurship among informatics engineering students: insights from a case study

Universities seek to promote entrepreneurship through effective education approaches, which need to be in permanent evolution. Nevertheless, the literature in entrepreneurship education lacks empirical evidence. This article discusses relevant issues related to promoting entrepreneurship in the software field, based on the experience of a 15-European Credit Transfer and Accumulation System course. This course seeks to instil in the students the recognition of the need to reconcile technical and business visions, organisational and commercial aspects, most of which have never been addressed previously. A series of semi-structured interviews made it possible to obtain relevant insights about the teaching–learning process underlying this course and its evolution over a seven-year period. Materials related with this course have been analysed, namely guidelines produced by the teachers and deliverables produced by the students. This article discusses the dimensions that were identified as fundamental for promoting entrepreneurship skills in the field of software, namely teamwork, project engagement, and contact with the market

EAGP: An energy-aware gossip protocol for wireless sensor networks

In Wireless Sensor Networks (WSN), typically composed of nodes with resource constraints, leveraging efficient processes is crucial to enhance the network lifetime and, consequently, the sustainability in ultra-dense and heterogeneous environments, such as smart cities. Particularly, balancing the energy required to transport data efficiently across such dynamic environments poses significant challenges to routing protocol design and operation, being the trade-off of reducing data redundancy while achieving an acceptable delivery rate a fundamental research topic. In this way, this work proposes a new energy-aware epidemic protocol that uses the current state of the network energy to create a dynamic distribution topology by self-adjusting each node forwarding behavior as eager or lazy according to the local residual battery. Simulated evaluations demonstrate its efficiency in energy consumption, delivery rate, and reduced computational burden when compared with classical gossip protocols as well as with a directional protocol.FCT -Fundação para a Ciência e a Tecnologia(UIDB/50014/2020

Concise server-wide causality management for eventually consistent data stores

Large scale distributed data stores rely on optimistic replication to scale and remain highly available in the face of net work partitions. Managing data without coordination results in eventually consistent data stores that allow for concurrent data updates. These systems often use anti-entropy mechanisms (like Merkle Trees) to detect and repair divergent data versions across nodes. However, in practice hash-based data structures are too expensive for large amounts of data and create too many false conflicts. Another aspect of eventual consistency is detecting write conflicts. Logical clocks are often used to track data causality, necessary to detect causally concurrent writes on the same key. However, there is a nonnegligible metadata overhead per key, which also keeps growing with time, proportional with the node churn rate. Another challenge is deleting keys while respecting causality: while the values can be deleted, perkey metadata cannot be permanently removed without coordination. Weintroduceanewcausalitymanagementframeworkforeventuallyconsistentdatastores,thatleveragesnodelogicalclocks(BitmappedVersion Vectors) and a new key logical clock (Dotted Causal Container) to provides advantages on multiple fronts: 1) a new efficient and lightweight anti-entropy mechanism; 2) greatly reduced per-key causality metadata size; 3) accurate key deletes without permanent metadata.(undefined

DottedDB: anti-entropy without merkle trees, deletes without tombstones

To achieve high availability in the face of network partitions, many distributed databases adopt eventual consistency, allow temporary conflicts due to concurrent writes, and use some form of per-key logical clock to detect and resolve such conflicts. Furthermore, nodes synchronize periodically to ensure replica convergence in a process called anti-entropy, normally using Merkle Trees. We present the design of DottedDB, a Dynamo-like key-value store, which uses a novel node-wide logical clock framework, overcoming three fundamental limitations of the state of the art: (1) minimize the metadata per key necessary to track causality, avoiding its growth even in the face of node churn; (2) correctly and durably delete keys, with no need for tombstones; (3) offer a lightweight anti-entropy mechanism to converge replicated data, avoiding the need for Merkle Trees. We evaluate DottedDB against MerkleDB, an otherwise identical database, but using per-key logical clocks and Merkle Trees for anti-entropy, to precisely measure the impact of the novel approach. Results show that: causality metadata per object always converges rapidly to only one id-counter pair; distributed deletes are correctly achieved without global coordination and with constant metadata; divergent nodes are synchronized faster, with less memory-footprint and with less communication overhead than using Merkle Trees.This work is financed by the ERDF – European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 Programme within project «POCI-01-0145-FEDER-006961», and by National Funds through the Portuguese funding agency, FCT - Fundação para a Ciência e a Tecnologia as part of project «UID/EEA/50014/2013».info:eu-repo/semantics/publishedVersio

Optimized planning of different crops in a field using optimal control in Portugal

Climate change is a proven fact. In the report of 2007 from IPCC, one can read that global warming is an issue to be dealt with urgently. In many parts of the world, the estimated rise of temperature (in a very near future) is significant. One of the most affected regions is the Iberian Peninsula, where the increasing need for water will very soon be a problem. Therefore, it is necessary that decision makers are able to decide on all issues related to water management. In this paper, we show a couple of mathematical models that can aid the decision making in the management of an agricultural field at a given location. Having a field, in which different crops can be produced, the solution of the first model indicates the area that should be used for each crop so that the profit is as large as possible, while the water spent is the smallest possible guaranteeing the water requirements of each crop. Using known data for these crops in Portugal, including costs of labour, machines, energy and water, as well as the estimated value of the products obtained, the first mathematical model developed, via optimal control theory, obtains the best management solution. It allows creating different scenarios, thus it can be a valuable tool to help the farmer/decision maker decide the crop and its area to be cultivated. A second mathematical model was developed. It improves the first one, in the sense that it allows considering that water from the rainfall can be collected in a reservoir with a given capacity. The contribution of the collected water from the rainfall in the profit obtained for some different scenarios is also shown.The authors were supported by POCI-01-0145-FEDER-006933-SYSTEC, PTDC/EEI-AUT/2933/2014, POCI-01-0145–FEDER-016858 TOCCATTA and POCI-01-0145-FEDER-028247 To Chair–funded by FEDER funds through COMPETE2020—Programa Operacional Competitividade e Internacionalizaça˜ o (POCI) and by national funds (PIDDAC) through FCT/MCTES, which is gratefully acknowledged. Financial support from the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Financing UID/FIS/04650/2013 is also acknowledged. The authors also thank SMARTEGOV Project (P2020 NORTE-45-2015-23) Harnessing EGOV for smart governance. Acknowledgments The authors acknowledge the Department of Mathematics, the Centre of Physics, INESC TEC, from the University of Minho, Systec—Research Center for Systems and Technologies, from the University of Porto, UNU-EGOV Portugal and LEMA-ISEP, Instituto Politécnico do Porto.info:eu-repo/semantics/publishedVersio

Dataset associated with "Land use conversion to agriculture impacts biodiversity, erosion control and key soil properties in an Andean watershed"

This data set involves soil and plant variables collected from 50 farm and forest plots in a mountainous region of the Valle del Cauca Department of Colombia. Sampling was conducted in 2016 to evaluate soil biodiversity and ecosystem services provided across five dominant land uses in the region.The conversion of natural vegetation to agricultural land uses in mountainous Andean landscapes threatens an array of key ecological processes and ecosystem services. In protected areas and buffer regions that provide water to cities, it is critical to understand how interactions between plants and soil communities sustain a range of ecosystem functions, associated with nutrient recycling, soil structure, and erosion control. We sought to understand how land use conversion within a mountainous tropical forest landscape influences the diversity of vegetation and soil macrofauna communities, soil physico-chemical properties, and hydrological regulation services. Biodiversity and a suite of key soil-based ecosystem services were compared in five major land uses of the Cali River watershed: 1) annual cropping systems, 2) coffee plantations, 3) pastures, 4) abandoned shrubland, and 5) secondary forests. The diversity of woody and herbaceous vegetation, as well as soil macrofauna was assessed in each land use. Soil chemical fertility and aggregate morphology were assessed via laboratory analyses and visual separation of soil aggregates based on their origin. Infiltration, runoff, and sediment production were measured using a portable rainfall simulator. We found a decrease in the diversity of woody vegetation across land-uses to be associated with lower diversity of soil macrofauna. At the same time, agricultural management, annual crops in particular, supports the largest earthworm populations, likely due to increased organic inputs and low impact tillage, which appears not to diminish soil fertility and water infiltration. In contrast, the low soil fertility in pastures was associated with the lowest values of soil C, poor aggregation, and high bulk density, and likely reflects overgrazing, with negative implications for water infiltration and erosion. Associations between the different sets of variables, evaluated with a co-inertia analysis, highlights the hierarchical relevance of plant cover and woody diversity on ecosystem services. The biological complexity associated with intact forest cover appears to generate "bundles" of co-occurring ecosystem services, with this land use demonstrating the highest infiltration, and low runoff and sediment losses. Our findings demonstrate that forests and tree-based agricultural systems may better contribute to the provision of multiple ecosystem services, including biodiversity conservation and hydrologic regulation