A key enabler for the digitization of physical devices is digital twining technology. A digital twin is a virtual representation of a physical object (or a collection of physical objects) that allows their integration into cyber systems. Digital twins are usually hosted in cloud environments, which provide high availability and resilience to failures. This integration creates new opportunities and enables new capabilities, but it also raises security concerns. In this paper, we design a digital certificate management solution that allows building trust on digital twins independently of their network location. Our solution allows digital twins to securely receive certificates, which can be used to digitally sign data at the application layer. Our scheme does not depend on the certificate infrastructure used to secure the communication between end-users and the (cloud-hosted) digital twins. Our solution is feasible, realistic and resilient against key breaches, with a marginal communication overhead. Finally, our scheme automates the process of certificate issuance for digital twins, thus enabling very fast key and certificate rotation.

The Secure Named Data Sharing (SNDS) architecture is a content brokering service built on top of Named-Data Networking (NDN), leveraging its native support for multicast, multisource and caching. SNDS transparently supports IP-based content providers and consumers via a gateway that implements ETSI’s NGSI-LD data spaces API, translating HTTP requests to and from the appropriate NDN messages. To fully support the query-based NGSI-LD API, we build appropriate protocols over NDN. We present a prototype implementation of the SNDS architecture and a preliminary evaluation of its features.

The proliferation of Internet of Things (IoT) devices that operate unattended providing a multitude of important and often sensitive services highlights the need for seamless interoperability and increased security. We argue that digital twins of IoT devices, with the right design, can enhance the security, reliability, auditability, and interoperability of IoT systems. The salient features of digital twins have made them key elements for the IoT and Industry 4.0. In this paper, we leverage advances in W3C's Web of Things (WoT) standards and Distributed Ledger Technologies (DLTs) to present a novel design of smart contract-based digital twins with enhanced security, transparency, interoperabilty, and reliability. We provide two different variations of that general design using two different blockchains (one public and one private, permissioned blockchain), and we present design trade-offs. Furthermore, we introduce an architecture for accessing and controlling IoT devices securely, reliably, providing full auditability, while at the same time using the proposed digital twins as an indirection mechanism (proxy). The proposed architecture leverages the blockchain to offer notable properties, namely, decentralization, immutability, auditability, non-repudiation, availability, and reliability. Moreover, it introduces mass actuation, easier management of IoT devices, enhanced security to the IoT gateways, it enables new business models, and it makes consumer devices (vendor-)agnostic.

Digital Twins and the Internet of Things (IoT) are two of the most prominent recent concepts and technologies. The IoT supports many applications that merge the physical with the cyber world. This highlights the need for improved security. Here, we argue that digital twins can help in securing and strengthening the IoT by using them for interacting with the actual IoT devices. While most digital twins implementations are centralized, we propose to integrate Distributed Ledger Technologies (DLTs) and digital twins into the IoT to realize decentralized, secure, available, flexible, and auditable blockchain-based IoT services for IoT devices that follow the W3C Web of Things (WoT) standards. In this work, we present the design of SmartTwin, a blockchain-based digital twin framework for which we provide two different implementations using two different blockchains, we present the design trade-offs, and we discuss future research and development directions.

The proliferation of Internet of Things (IoT) devices and applications that need to cooperate unattended highlights the need for seamless interoperability and intrinsic security. We argue that Distributed Ledger Technologies (DLTs), due to their decentralized nature, transparent operations, immutability, and availability, can enhance the security, reliability, and interoperability of such IoT systems. In this paper, we advance the integration of W3C's Web of Things (WoT) standards with DLTs and smart contracts, introducing smart contracts as “Digital Twins” of (physical) devices, or whole Cyber-Physical subsystems. Namely, we introduce a DLT-based architecture for controlling devices across federated IoT systems, securely, reliably, and with full auditability. The proposed architecture provides mass actuation and service composition with notable security properties, such as full auditability, transparency, and high availability. Specifically, a single request, with multiple action parameters and conditions, can trigger the reliable and secure actuation of a large number of possibly physically dispersed actuators.

We leverage the InterPlanetary File System (IPFS) and Non-Fungible Tokens (NFTs) backed by Distributed Ledger Technologies (DLTs) to build a flexible, decentralized, and fair baseline system for trading games. Our solution creates a fully decentralized system, where new business models are enabled, as the evolvable assets of the games can be resold and priced depending on their rarity, giving also a cut to the digital artist, without the need for a trusted party. The system guarantees that assets will remain online, thus the users do not risk losing control over the artefacts or their value, even if the creator game company loses interest or goes bankrupt.

Service providers usually require detailed statistics in order to improve their services. On the other hand, privacy concerns are intensifying and sensitive data is protected by legislation, such as GDPR (General Data Protection Regulation). In this paper, we present the design, implementation, and evaluation of a marketplace that allows “data consumers” to buy information from “data providers”, which can then be used for generating meaningful statistics. Additionally, our system enables “system operators” that can select which data providers are allowed to provide data, based on filtering criteria specified by the data consumer. We leverage local differential privacy to protect the data provider's privacy against data consumers, as well as against system operators, and we build a blockchain-based solution for ensuring fair exchange, and immutable data logs. Our design targets use cases that involve hundreds or even thousands of data providers. We prove the feasibility of our approach through a proof-of concept implementation of a measurement sharing application for smart-grid systems.

Blockchains and smart contracts are an emerging, promising technology, that has received considerable attention. We use the blockchain technology, and in particular Ethereum, to implement a large-scale event-based Internet of Things (IoT) control system. We argue that the distributed nature of the “ledger,” as well as, Ethereum's capability of parallel execution of replicated “smart contracts”, provide the sought after automation, generality, flexibility, resilience, and high availability. We design a realistic blockchain-based loT architecture, using existing technologies while by taking into consideration the characteristics and limitations of IoT devices and applications. Furthermore, we leverage blockchain's immutability and Ethereum's support for custom tokens to build a robust and efficient token-based access control mechanism. Our evaluation shows that our solution is viable and offers significant security and usability advantages.