## 4 Results: Proof of Concept
### Identity Management Implementation
#### 4.1.3 Verifiable Presentations (VPs)
The successful implementation of decentralized identity solutions within IOTA demonstrates the potential of distributed ledger technologies (DLTs) to advance Web 3.0 paradigms. By promoting data sovereignty, security, and interoperability, decentralized identity frameworks can transform the way digital identities are managed in various domains, including healthcare, smart cities, and beyond. Our findings contribute to the broader discourse on the adoption of decentralized technologies and highlight the need for continued research and development in this area. Future research should explore the optimization of cryptographic schemes for resource-constrained devices, the integration of advanced communication protocols, and the scalability of decentralized identity systems in diverse IoT environments. ## 8 Conclusions

This study validated the effectiveness of using decentralized identity models supported by IOTA's DAG-based architecture to enhance security, scalability, and privacy in IoT ecosystems. By integrating Decentralized Identifiers (DIDs), Verifiable Credentials (VCs), and IOTA-specific technologies such as IOTA Identity, IOTA Streams, and IOTA Stronghold, we have demonstrated a proof-of-concept decentralized identity management system tailored for IoT devices. The proposed framework addresses the inherent limitations of traditional centralized identity management systems, including single points of failure, limited scalability, and privacy concerns. By leveraging the unique properties of IOTA, such as feeless transactions and high scalability, our approach ensures that identity management operations are both cost-effective and capable of handling the high volume of transactions typical of IoT environments. The integration of techniques for managing heterogeneous blockchains, such as those discussed in [30], provides valuable insights for improving the interoperability of decentralized identity systems. In particular, approaches such as the resource-oriented strategy for blockchain integration in intertwined supply chains provide a foundation for addressing scalability and data consistency challenges in IoT ecosystems. Similarly, balancing on-chain and off-chain data, as explored in [31], is critical to ensuring efficient data management. This balance is particularly important for IoT, where large amounts of non-critical data must be stored off-chain while essential metadata and cryptographic proofs are maintained on-chain for validation and trust. Smart contract design, as outlined in [32; 33; 34], also provides actionable guidance for enhancing the proposed framework. For example, a three-layer approach to smart contract design [32] could optimize the processes of device registration, verification, and credential issuance, while business process execution engines such as Caterpillar [33] could provide a robust mechanism for managing complex IoT workflows. In addition, the use of blockchain in collaborative business processes [34] demonstrates how such systems can be adapted to IoT environments, ensuring seamless collaboration and trust between heterogeneous devices. Key findings from our study include the successful implementation of DIDs and VCs on a resource-constrained IoT device, secure real-time data exchange using IOTA Streams, and robust key management using IOTA Stranghold. Together, these components enhance the security and privacy of IoT devices and provide a decentralized framework that gives users control over their digital identities. The implications of our research extend to the broader context of Web 3.0, which emphasizes decentralization, user autonomy, and data sovereignty. Web 3.0 envisions a more secure and user-centric Internet where individuals have greater control over their data and interactions online. Our study's integration of IOTA's decentralized identity solutions aligns with these principles by eliminating reliance on centralized authorities, enhancing privacy, and promoting trusted interactions.