## 4 Results: Proof of Concept
### Identity Management Implementation
#### 4.1.3 Verifiable Presentations (VPs)
While the IOTA approach used in this study also has higher resource consumption compared to some lighter solutions, it is still more efficient than these other frameworks when integrated into IoT systems. Unlike IOTA, which is specifically designed for resource-constrained environments and optimized for scalability and security in IoT systems, these frameworks were not developed with such integration in mind. As a result, their use in IoT ecosystems often results in performance bottlenecks, higher power consumption, and increased latency. IOTA's lightweight architecture, fuzzy transactions, and efficient consensus mechanisms provide distinct advantages in terms of resource optimization, making it better suited to the specific needs of IoT applications. Therefore, while other decentralized identity frameworks may offer some capabilities, their integration into IoT environments would introduce inefficiencies that IOTA is specifically designed to mitigate. ### Architectural Advantages

IOTA's Directed Acyclic Graph (DAG)-based Tangle represents a fundamental departure from traditional blockchain architectures. Unlike blockchain systems, where transactions are grouped into blocks and appended sequentially, the Tangle processes transactions asynchronously. Each transaction validates two previous transactions, creating a parallel processing mechanism that eliminates the bottlenecks inherent in blockchain architectures. This design allows IOTA to achieve high scalability and efficiency, making it particularly suitable for IoT environments where devices generate frequent, small-scale data exchanges. In comparison, Ethereum and Hyperledger Indy rely on linear, block-based designs that can face throughput limitations as network activity increases [25]. Comparison of DAG Over Blockchain for IoT Applications. The DAG-based Tangle replaces Merkle trees and sequential hashing algorithms with a decentralized structure optimized for IoT applications. Table 2 provides a comprehensive comparison of IOTA's architecture with blockchain-based systems, highlighting its unique advantages:

1. Feeless Transactions: IOTA eliminates transaction fees, enabling cost-effective micro-transactions for IoT. In contrast, Ethereum-based frameworks like ERC-725 impose gas fees for every transaction, significantly increasing costs for high-frequency interactions. 2. Parallel Processing: The Tangle's asynchronous validation allows transactions to be processed concurrently, avoiding the bottlenecks of block creation and mining found in traditional blockchains. 3. Elimination of Mining: By not requiring energy-intensive mining for consensus, IOTA achieves significantly lower energy consumption, making it suitable for low-power IoT devices. These advantages position IOTA as an ideal candidate for decentralized identity management in resource-constrained IoT ecosystems. ### Cost Efficiency

IOTA's feeless transaction model is a standout feature for IoT environments, where devices often operate under tight cost constraints. Ethereum-based systems like ERC-725, which rely on gas fees for transactions, can become prohibitively expensive for IoT use cases that require frequent communication. Similarly, Hyperledger Indy's reliance on network maintenance costs inherent to permissioned blockchains makes it less cost-effective for lightweight IoT operations. IOTA's approach ensures minimal operational costs without compromising scalability or security [26]. Identity-Specific Features

IOTA Identity seamlessly integrates with the Tangle to provide Decentralized Identifiers (DIDs) and Verifiable Credentials (VCs), enabling secure and verifiable identity management tailored for the IoT. Unlike Ethereum's ERC-725, which serves as a general-purpose framework, IOTA Identity focuses on IoT-specific requirements such as lightweight implementation and real-time data exchange. While Hyperledger Indy excels at Verifiable Credentials, its reliance on resource-intensive blockchain mechanisms poses challenges for IoT devices with limited computing and power capabilities [25].