While IoT systems are increasingly present in different areas of society, ensuring their data’s privacy, security, and inviolability becomes paramount. In this direction, Blockchain has been used to protect the security and immutability of data generated by IoT devices and sensors. At the heart of Blockchain solutions, consensus algorithms are crucial in ensuring the security of creating and writing data in new blocks. Choosing which consensus algorithms to utilise is critical because of a fundamental tradeoff between their security strength and response time. However, recent surveys of consensus mechanisms for IoT-based Blockchain focused on individually using and analysing these algorithms. Investigating the integration between these algorithms to address IoT-specific requirements better is a promising approach. In this context, this paper presents a literature review that explains and discusses consensus algorithms in IoT environments and their combinations. The review analyses eight dimensions that help understand existing proposals: ease of integration, scalability, latency, throughput, power consumption, configuration issues, integrated algorithms, and adversary tolerance. The final analysis also suggests and discusses open challenges in integrating multiple consensus algorithms considering the particularities of IoT systems.

Education generates a considerable amount of data and information, it is necessary to manage this data securely, avoiding problems of falsification and tampering with diplomas, certificates, and other important student documents. In addition, distance learning is becoming more popular due to the Covid-19 pandemic period, where courses are offered in virtual learning environments such as Moodle. Blockchain technology can be used as a tool to ensure the security of data managed by Moodle. However, there is a gap in current state-of-the-art solutions for integrating these data with Blockchain platforms. This work proposes BlockMoodle, a solution developed to integrate Moodle with Blockchain Ethereum. This work also performs an analysis of the financial cost of using the tool. In addition, a performance evaluation of the proposed solution is also carried out considering different usage scenarios. Finally, the conclusions and future work to be developed are presented.

This work presents the proposal to develop the Connected EJA tool, created for use in the classroom as an aid to the pedagogical practices of the teacher, contributing to the process of literacy in Youth and Adult Education. The tool is based on Paulo Freire's literacy method, which considers students with their life experiences and forms of knowledge of the literate world. The different types of content are presented, organized in modules, with interactive activities that allow the student to practice reading, comprehension and text production skills, as well as the design resources used in programming. Este trabalho apresenta a proposta de desenvolvimento da ferramenta EJA Conectada, criada para uso em sala de aula como auxílio as práticas pedagógicas do professor, contribuindo, no processo de alfabetização na Educação de Jovens e Adultos (EJA). A ferramenta é baseada no método de alfabetização de Paulo Freire que considera os alunos com suas experiências de vida e formas de conhecimento do mundo letrado. São apresentados os diversos tipos de conteúdo, organizados em módulos, com atividades interativas que permitem ao aluno praticar as habilidades de leitura, compreensão e produção de textos, assim como os recursos de design utilizados na programação.

A Internet das Coisas (IoT) consiste em um sistema de cooperação entre dispositivos inteligentes conectados. Os sistemas IoT têm acesso a diversos dados dos usuários, que precisam ser gerenciados de forma eficiente para evitar vulnerabilidades de segurança. Nesse cenário, a tecnologia Blockchain apresenta-se como uma opção promissora, pois permite o registro de dados de forma descentralizada, criptografada e imutável. Diante disso, este trabalho apresenta uma simulação de Blockchain utilizada para registros de dados da IoT e realiza uma avaliação de desempenho sobre ela, comparando com resultados da literatura. Foi realizada uma revisão bibliográfica, onde um trabalho foi escolhido como base para o comparativo de desempenho, em seguida foram definidas as métricas de avaliação, que foram vazão e tempo de resposta. Foram executados diferentes testes de carga sobre a Blockchain, variando sua quantidade de nós. Por fim, os resultados obtidos foram comparados com os dados do artigo de referência.