Blockchain technologies and the Semantic Web

The full day tutorial on Blockchain technologies and the Semantic Web will take place during the 18th International Conference on Semantic Web (ISWC 2019) on October 26th/27th, 2019.


The web and the semantic web are the most significant cases of environments where the information is distributed. In parallel, in the recent year we observed the rise of blockchain as a way to distribute assets and trust. It is therefore normal to ask ourselves: how are semantic web and blockchain different? Can they complement each other? In this tutorial, we want to analyse such questions from the semantic web perspective, with two goals: (i) understand how blockchain research can help semantic web to address its open challenges (e.g. trust and identity management), and (ii) understand how semantic web research can contribute to the blockchain development (e.g. annotations and data integration).

The tutorial will target semantic web researchers with limited knowledge about blockchain: we will introduce the main concepts behind blockchain, and present successful use cases. Next, we will focus on the overlap between blockchain and semantic web, with an overview of ongoing research and results. Attendees will put in practice what they learned through hands-on sessions and demos. Finally, the tutorial will provide a space for discussion about future research directions.



Welcome and introduction (5 minutes)

The first session offers an overview of blockchains - historical background, promises, successful use cases. The session also introduces the tutorial: we will give an overview of the program and the presenters.

[slides (PDF, 232 KB)]

From cryptocurrencies to smart contract (75 minutes)

This session covers the main concepts related to blockchains, such as: blocks, decentralized consensus, identity management, mining and proof-of-work. The session will also focus on smart contracts, their role in the blockchain ecosystem and their structure.

Blockchain and Semantic Web (80 minutes)

This session explores the similarities, differences, and complementarities between Blockchain and the Semantic Web, with particular emphasis on Semantic Web research questions that could be approached with blockchain technology and vice-versa. The section will also present an overview of papers that explore this common space.

[slides (PDF, 1 MB)]

Hands-on session 1 (90 minutes)

The first hands-on session will be comprised of two tasks where participants will learn how a blockchain can be used to store and verify RDF data. In the first task, participants will be given a web interface and will follow a set of steps guiding them in storing sample RDF data into a Smart Contract. In the second task, attendees will learn on how RDF data that has previously been stored on a blockchain can be verified to confirm that it has not been tampered with. All the APIs used for these exercises will be available, through a web interface, for participants to explore and interact with independently.

Hands-on session 2 (45 minutes)

In the second hands-on session, attendees will learn how to use Solid to store and verify RDF data in conjunction with a blockchain. Participants will start by creating their own Solid accounts, and will then follow a guided exercise where they will store some sample RDF data into their own Solid ‘data pod’. Subsequently, participants will be guided through a series of steps where a combination of Smart Contracts and blockchain tokens are used to represent and verify the RDF data previously stored in Solid. Each participant will be provided with their own blockchain visualiser, enabling them to see what is happening in the blockchain network as their transactions are executed, including the mining of new blocks.

Discussion and wrap-up (5 minutes)

This session will encourage discussion among attendees and tutors about perspectives on Blockchains and the Semantic Web. We will involve the attendees in a discussion to collect opinions, thoughts, and research questions.

Audience and pre-requisites

The tutorial targets researchers and practitioners interested in approaching the topic of blockchain, and who want to understand the current state of the art as well as future directions.

We expect you have basic knowledge of Semantic Web concepts (e.g. RDF, SPARQL and Linked Data principles), and you are familiar with at least one programming language.