Blockchain and Distributed Ledger Technologies

Welcome to the website of “Blockchain and Distributed Ledger Technologies”, a course of the MSc programmes in
Computer Science and Cybersecurity at the Sapienza University of Rome.

Course description

Introduction

Blockchains emerged as a novel, game-changing paradigm for the distributed management of transactional systems. A blockchain is a protocol for the decentralised storage of a tamper-proof sequence of transactions (ledger), maintained and verified by the nodes participating in the network. The sequence of transactions corresponds to the actions that modify the status of the blockchain. A combination of peer-to-peer networks, consensus-making, cryptography, and market mechanisms is at the core of blockchains, which thereby ensure data integrity and transparency and propel a new paradigm known as cryptoeconomics. First-generation blockchains such as Bitcoin mainly focus on the exchange of electronic cash through cryptocurrencies. Second-generation blockchains such as Ethereum support so-called smart contracts, that is, executable code expressing how business is to be conducted among contracting parties (e.g., transfer digital assets after a condition is fulfilled). The number of advantages brought by this new capability led to an array of blockchain-based platform services catering for processes in the financial sector, the management of identities, energy distribution and supply chains, among others. The design of a secure, verifiable and efficient blockchain-based application requires the capability of properly architecting the behavioural structures among the involved parties. 

Objectives

Students will learn the basics of blockchain technologies and the interplay of the underlying techniques that lead to the immutability, persistency, security and eventual consistency of the blockchain platforms. Furthermore, they will learn how to encode smart contracts and, thereupon, create full-stack Decentralised Applications (DApps). To properly design DApps and the token systems they rely upon, learners will apply the principles of process behaviour modelling and execution. To that end, an overview of cybersecurity challenges will also be provided. Furthermore, the learners will look at the covered topics from a legislative standpoint in order to consider normative challenges, including compliance with users’ privacy.

Teaching methods

The course will combine alternative ways to deliver the topics to students. On the one hand, a classical frontal-lecture style approach will be adopted to present the fundamental notions and case studies; on the other hand, students will have to solve hands-on exercises in class and as homework. At the end of the course, students will present the outcome of their teamwork in which a DApp is devised, designed and implemented.

Evaluation

The evaluation will be based on:

• individual classwork with open-ended and closed-ended questions for self-assesment; 

• the consignment of a project showing an implemented distributed application, with a written report illustrating the motivation, rationale and architectural design choices;

• an intermediate presentation of the project to be held at the end of the course;

• a written test on general blockchain and distributed ledger technology core concepts.

Prerequisites

Basic knowledge of mathematics, algebra and computer science acquired during the Bachelor of Science in Computer Science or Applied Computer Science and Artificial Intelligence are necessary. In particular, the students should be knowledgeable in the concepts of:

• Programming

• Algorithms

• Software engineering

• Computer Architectures

• Data Management and Analysis

Course contents

The course will consist of three main parts: 1) fundamentals of blockchains and their underlying technologies; 2) smart contracts programming; 3) development of a full-stack blockchain-based application. More in detail, the course content will be based on the following subjects, although the specific contents could be subject to modifications:

1. Course objectives and definitions

2. Introduction to blockchains

3. Preliminary notions

4. A historical view of blockchains

5. The transaction, the ledger, the block

6. Blockchain consensus

7. Block validation and forking

8. Cryptoeconomics

9. Hashing

10. Smart contracts part 1 (definition, essentials)

11. Smart contracts part 2 (basics of smart contract programming)

12. Smart contracts part 3 (data types, logging)

13. Smart contracts part 4 (inheritance, exceptions)

14. Decentralised Applications part 1 (software architecture, introduction to Web3)

15. Decentralised Applications part 2 (token engineering)

16. Decentralised Applications part 3 (interfacing smart contracts to the web)

17. DAOs, the DAO and other uh-oh moments

Other topics will be discussed during the course are:

18. Oracles

19. Designing multi-party processes for the blockchain

20. Implementing processes on the blockchain

21. Smart contract security: vulnerabilities and exploits

22. Security best practices for smart contracts

23. Decentralised finance

24. GDPR and the blockchain