## 4 Results: Proof of Concept
### Identity Management Implementation
#### 4.1.3 Verifiable Presentations (VPs)
### Effectiveness of IOTA-Based Decentralized Identity

Our research confirms that the IOTA Tangle, with its Directed Acyclic Graph (DAG)-based architecture, provides a robust foundation for decentralized identity management. Unlike traditional blockchain systems, IOTA's fine-grained transactions and high scalability are particularly advantageous for IoT environments, where cost efficiency and low latency are critical. The proof-of-concept implementation on a Raspberry Pi demonstrated that DIDs and VCs can be effectively managed using IOTA Identity, ensuring secure device authentication and data exchange. The adoption of Self-Sovereign Identity (SSI) principles supported by IOTA gives users full control over their digital identities, mitigating the risks associated with centralized identity providers. This decentralization aligns with the Web 3.0 emphasis on user autonomy and data sovereignty, promoting a more secure and user-centric approach to identity management in IoT networks. ### Scalability and Performance

The scalability of the IOTA Tangle was a key focus of our study. Our results show that IOTA's architecture can handle a high volume of transactions without the bottlenecks typical of traditional blockchains. This capability is critical for IoT applications, where millions of devices generate frequent, small transactions. The lightweight nature of the Tangle makes it suitable for resource-constrained IoT devices, ensuring that identity management operations do not overwhelm the system's computing resources. In addition, the use of IOTA Streams for secure, decentralized data transfer between IoT devices demonstrated the low-latency communication essential for real-time applications. The integration of IOTA Stranghold for secure key management further ensured the integrity and confidentiality of cryptographic operations, improving the overall security posture of the IoT network. ### Ensuring Data Integrity and Immutability

Data immutability in the Tangle is achieved through cryptographic binding and consensus mechanisms. Once a transaction is added and validated by multiple nodes, its cumulative weight increases, making it tamper-proof. The Markov Chain Monte Carlo (MCMC) algorithm ensures that nodes probabilistically select valid transactions for approval, maintaining the consistency and integrity of the ledger. Together, these mechanisms secure the Tangle against malicious attacks and ensure consistent data storage across the distributed network. ### Efficient Data Storage Strategies in IoT Systems

IoT devices generate vast amounts of data but typically produce small chunks of information at a time. To address this, the proposed system adopts a hybrid storage model:

1. Metadata on Tangle: Critical identity data, such as DIDs, VCs, and cryptographic proofs, are stored on the Tangle to leverage its decentralized and tamper-proof properties. 2. External Storage: Bulk data or less critical information is stored externally, either on cloud services or local databases, to reduce the load on the Tangle. The Tangle stores metadata pointers to this external data, ensuring seamless integration and accessibility. ## 6 Comparative Analysis: IOTA vs. Other Decentralized Identity Solutions

IOTA's approach to decentralized identity management differs significantly from other solutions, such as Hyperledger Indy and Ethereum's ERC-725, in its architecture and design principles. These differences highlight IOTA's unique suitability for IoT ecosystems, especially in resource-constrained environments. The comparison with other decentralized identity frameworks, such as Hyperledger Indy or Ethereum-based solutions, is challenging in the context of the IoT system presented in this paper due to significant differences in resource consumption. As noted in the literature, these alternative frameworks typically have higher computing and memory requirements, which are not well suited for low-resource IoT devices such as Raspberry Pi.