## 4 Results: Proof of Concept
### Identity Management Implementation
#### 4.1.3 Verifiable Presentations (VPs)
This alignment with Web 3.0 principles not only enhances the security and scalability of IoT systems but also paves the way for more innovative and user-empowered applications in various domains, including smart cities, healthcare, and supply chain management. Our study has significant implications for the evolving landscape of Web 3.0, which focuses on decentralization, user control, and data ownership. Web 3.0 aims to create a more secure and user-centric Web environment where individuals have greater control over their online data and interactions. By integrating IOTA's decentralized identity solutions, our research supports these goals by removing reliance on central authorities, thereby enhancing privacy and promoting trusted interactions. This alignment with Web 3.0 concepts not only strengthens the security and scalability of IoT infrastructures but also opens the door to more innovative and user-driven applications in areas as diverse as smart cities, healthcare, and supply chain management. Despite the promising results, the study also identified several challenges, including the high computational demands of cryptographic operations on low-power devices and the need for the better integration of communication protocols such as DIDComm. Future research should focus on optimizing cryptographic algorithms for resource-constrained environments, exploring the integration of advanced protocols, and expanding scalability assessments across diverse IoT environments. The study aligns with Web 3.0 principles by promoting decentralization, user autonomy, and data sovereignty through the use of decentralized identity systems such as DIDs and VCs supported by IOTA's Tangle architecture. These systems enhance trust and privacy in digital interactions, with applications in healthcare and smart cities, where they can improve secure data exchange and identity management. As mentioned above, future research should address challenges such as DIDComm integration by exploring other communication protocols and optimizing cryptographic operations for low-power IoT devices. In addition, a cost-benefit analysis of permanent versus non-permanent nodes for storing identity records is essential, considering the trade-offs between the stability and higher cost of permanent nodes versus the flexibility and lower cost of non-permanent nodes. In conclusion, this research contributes to the broader discourse on decentralized identity management in IoT systems, in line with Web 3.0 principles. The results underscore the potential of IOTA-based solutions to advance the vision of a secure, user-empoweredInternet, paving the way for further innovations in decentralized technologies and their applications in IoT ecosystems. Conceptualization, A.M.-L., T.R.-G. and H.M.; methodology, A.M.-L., N.G.-D. and T.R.-G.; validation, T.R.-G. and F.A.P. ; formal analysis, A.M.-L. and N.G.-D.; investigation, T.R.-G. and F.A.P. ; resources, H.M. and [PERSON]; writing--original draft preparation, [PERSON], [PERSON] and [PERSON]; writing--review and editing, T.R. [PERSON] and F.A.P. ; supervision, H.M. All authors have read and agreed to the published version of the manuscript. This work was supported by the Spanish Research Agency (AEI) under project Serverless4 HPC PID20203-152804 OB-I00/ AEI/10.13039/501100011033. Data are available upon request. The authors declare no conflicts of interest. ## References

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