56,908 research outputs found

    Exploiting Blockchains to improve Data Upload and Storage in the Cloud

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    Cloud computing is an information technology that enables different users to access a shared pool of configurable system resources and different services without physically acquiring them. Most industries nowadays such as banking, healthcare and education are migrating to the cloud due to its efficiency of services especially when it comes to data security and integrity. Cloud platforms encounter numerous challenges such as Data deduplication, Data Transmission, Data Integrity, VM Security, Data Availability, Bandwidth usage… etc. In this paper we have adopted the Blockchain technology - which is a relatively new technology - that emerged for the first time as the cryptocurrency Bitcoin and proved its efficiency in securing data and assuring data integrity. It is mostly a distributed public ledger that holds transactions data in case of Bitcoin. In our work blockchains are adopted in a different way than its regular use in bitcoin. Three of the major challenges in Cloud Computing and Cloud services are Data Deduplication, Storage and Bandwidth usage are discussed in this paper

    Transactions and data management in NoSQL cloud databases

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    NoSQL databases have become the preferred option for storing and processing data in cloud computing as they are capable of providing high data availability, scalability and efficiency. But in order to achieve these attributes, NoSQL databases make certain trade-offs. First, NoSQL databases cannot guarantee strong consistency of data. They only guarantee a weaker consistency which is based on eventual consistency model. Second, NoSQL databases adopt a simple data model which makes it easy for data to be scaled across multiple nodes. Third, NoSQL databases do not support table joins and referential integrity which by implication, means they cannot implement complex queries. The combination of these factors implies that NoSQL databases cannot support transactions. Motivated by these crucial issues this thesis investigates into the transactions and data management in NoSQL databases. It presents a novel approach that implements transactional support for NoSQL databases in order to ensure stronger data consistency and provide appropriate level of performance. The novelty lies in the design of a Multi-Key transaction model that guarantees the standard properties of transactions in order to ensure stronger consistency and integrity of data. The model is implemented in a novel loosely-coupled architecture that separates the implementation of transactional logic from the underlying data thus ensuring transparency and abstraction in cloud and NoSQL databases. The proposed approach is validated through the development of a prototype system using real MongoDB system. An extended version of the standard Yahoo! Cloud Services Benchmark (YCSB) has been used in order to test and evaluate the proposed approach. Various experiments have been conducted and sets of results have been generated. The results show that the proposed approach meets the research objectives. It maintains stronger consistency of cloud data as well as appropriate level of reliability and performance

    Health Block: A Blockchain Based Secure Healthcare Data Storage and Retrieval System for Cloud Computing

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    Data in healthcare domain is highly sensitive in nature. Besides, there is need for maintaining integrity of such data. Blockchain technology has emerged to solve the problem of data integrity and non-repudiation with immutable storage in distributed repository. Thus secure data storage and retrieval in cloud environments is made possible using blockchain implementation. There are many existing healthcare systems with blockchain integration found in the literature. However, there is need for a system that supports complete set of operations that are governed by smart contracts. Another important consideration is that end users should be able to operate healthcare system without the need for knowledge of blockchain technology. Towards this end, in this paper, we proposed a Blockchain based secure healthcare data storage and retrieval system known as HealthBlock for cloud computing environments. We defined smart contract with underlying structures and functions using Solidity language for Ethereum blockchain platform. We also proposed and implemented an algorithm known as Healthcare Transactions over Blockchain (HToB). This algorithm supports secure blockchain based data storage and retrieval governed by smart contracts. Our system is evaluated using user-friendly web based client application. The experimental results showed that our system is able to ensure data integrity and non-repudiation besides reaping all benefits of blockchain technology

    Efficient Transaction Processing for Short-Lived Transactions in the Cloud

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    The cloud, in the past few years, has become the preferred platform for hosting web applications. Many of these web applications store their data in a distributed cloud storage system, which greatly simplifies application development and provides increased availability and reliability. However, with increasing user demand for web applications, these cloud storage systems often become the performance bottleneck. To address the cloud's performance demands, many storage system features, such as strong consistency and transactional support, are often omitted in favour of performance. Nonetheless, transactions remain necessary to ensure data integrity and application correctness. In this thesis, we introduce CrossStitch, which is an efficient transaction processing framework for distributed key-value storage systems. CrossStitch supports general transactions, where transactions include both computation and key accesses. It is specifically optimized for short-lived transactions that are typical of cloud-deployed web applications. In CrossStitch, a transaction is partitioned into a series of components that form a transaction chain. These components are executed and the transaction is propagated along the storage servers instead of being executed on the application server. This chained structure, in which servers only communicate with their immediate neighbours, enables CrossStitch to implement a pipelined version of two-phase commit to ensure transactional atomicity. CrossStitch is able to eliminate a significant amount of setup overhead using this structure by executing the transaction and the atomic commit protocol concurrently. Therefore, CrossStitch provides low latency and efficient transactional support for cloud storage systems. Our evaluation demonstrates that CrossStitch is a scalable and efficient transaction processing framework for web transactions

    Data Migration from Relational Database to MongoDB

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    MongoDB is a document-oriented database which helps us group data more logically. This paper demonstrates the conversion of data from a native tabular form to unstructured documents. The document and collections within it needs not to be well defined prior to the creation of unstructured data in MongoDB. The MongoDB has lots of extensive built-in-features and is highly compatible with other software systems, with extensive and flexible ways of accessing data beyond JSON query, its highly compatible Business Intelligence Connector is highly compatible which makes it compatible with existing databases. High scalability is making it remarkable and popular in the World and hence made me think about writing a paper demonstrating the data conversion. This conversion has helped me in making the most of modern data to be compatible with MongoDB. Data is stored on the cloud as cloud-based storage is an excellent and most cost-effective solution. My solution is highly scalable as the built-in shading solution for data handling makes it one of the best big data handling tool. The data that i have used, is location based in MongoDB that can directly yeild document ACID transactions to maintain data integrity

    CD/CV: Blockchain-based schemes for continuous verifiability and traceability of IoT data for edge-fog-cloud

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    This paper presents a continuous delivery/continuous verifiability (CD/CV) method for IoT dataflows in edge¿fog¿cloud. A CD model based on extraction, transformation, and load (ETL) mechanism as well as a directed acyclic graph (DAG) construction, enable end-users to create efficient schemes for the continuous verification and validation of the execution of applications in edge¿fog¿cloud infrastructures. This scheme also verifies and validates established execution sequences and the integrity of digital assets. CV model converts ETL and DAG into business model, smart contracts in a private blockchain for the automatic and transparent registration of transactions performed by each application in workflows/pipelines created by CD model without altering applications nor edge¿fog¿cloud workflows. This model ensures that IoT dataflows delivers verifiable information for organizations to conduct critical decision-making processes with certainty. A containerized parallelism model solves portability issues and reduces/compensates the overhead produced by CD/CV operations. We developed and implemented a prototype to create CD/CV schemes, which were evaluated in a case study where user mobility information is used to identify interest points, patterns, and maps. The experimental evaluation revealed the efficiency of CD/CV to register the transactions performed in IoT dataflows through edge¿fog¿cloud in a private blockchain network in comparison with state-of-art solutions.This work has been partially supported by the project “CABAHLA-CM: Convergencia Big data-Hpc: de los sensores a las Aplicaciones” S2018/TCS-4423 from Madrid Regional Government, Spain and by the Spanish Ministry of Science and Innovation Project “New Data Intensive Computing Methods for High-End and Edge Computing Platforms (DECIDE)”. Ref. PID2019-107858GB-I00; and by the project 41756 “Plataforma tecnológica para la gestión, aseguramiento, intercambio preservación de grandes volúmenes de datos en salud construcción de un repositorio nacional de servicios de análisis de datos de salud” by the PRONACES-CONACYT, Mexic
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