Blockchain technologies and smart contracts in the context of the Internet of Things
Τεχνολογίες αλυσίδας συστοιχιών και έξυπνα συμβόλαια στο πλαίσιο του Διαδικτύου των Πραγμάτων
KeywordsΤεχνολογία αλυσίδας συστοιχιών ; Έξυπνα συμβόλαια ; Διαδίκτυο των Πραγμάτων ; Τεχνολογία κατανεμημένου καθολικού ; Μηχανισμοί ομοφωνίας ; Αξιολόγηση ασφάλειας ; Αξιολόγηση πλατφορμών τεχνολογιών αλυσίδας συστοιχιών ; Blockchain technology ; Smart contracts ; Internet of Things ; Distributed ledger technology ; Bitcoin ; Ethereum ; Consensus mechanism ; Security assessment ; Blockchain platform evaluation
Distributed ledger technology, is a set of technologies where a ledger is maintained by a number of peers without needing a single central authority. From this family of technologies, blockchain has recently become very popular. Blockchain is a distributed, transactional database which is shared across all the nodes of the network system , acting as a public ledger. Every node, usually most of the times has a full copy of the current blockchain , which contains every transaction that has ever been executed. Each block contains a hash of the previous block; the linking of those two together, constitutes the blockchain. This is the main technology underneath cryptocurrencies that started with Bitcoin. The recent focus on blockchain came as a result of the commercial success of Bitcoin and the consequent attention it caught by the researchers and industries. In this thesis we deal with the current status of the blockchain in addition to an application beyond cryptocurrencies, named smart contracts combined with IoT. Furthermore, we compare five blockchain platforms enabling smart contracts focusing on their general description, their main technological properties and their financial data. Additionally, we will perform a cost-benefit analysis and security assessment of smart contracts to highlight the related issues providing a set of possible solutions. Finally, we present a hands-on example to show the process and the flexibility in building smart contracts in an IoT environment.