## 6 Discussion  
The proposed implementation shows how a DLT technology can potentially serve as a transport and data layer protocol that enables data integrity. It showcases a decentralized IoT smart precision agriculture system, where each Super Node functions as an autonomous unit, aggregating data and participating in a M2M economy that exchanges services and data for value. IOTA, albeit its drawbacks, deems to be an excellent choice to serve as the infrastructure to support a decentralized transfer of value and data, in a manner that is publicly auditable.  
IOTA is a pioneer in implementing a DAG structure, in lieu of blockchain, as the immutable ledger of the network and it is an novel approach on bringing such a system to consensus and eliminate the need for miners and for transaction fees. As the Tangle is not functioning in a truly  
Figure 23: Precision Agriculture Use Case.  
decentralized fashion, the IOTA foundation operates a special node called \"The Coordinator\" that is responsible for issuing milestone transactions on specific intervals [46]. Currently transactions are not approved by the network using a consensus algorithm, but their confirmation depends solely on whether they are referenced (directly or indirectly) by a milestone transaction. Although the IOTA foundation claims that this step is necessary to protect the network until it reaches a safe critical mass, critics make a point that \"the Coordinator\" could actually censor specific transactions by not referencing them [47]. Another important question raised is the question of cryptographic maturity of the project. IOTA introduced a large number of novelties, amongst them being the use of a ternary system instead of binary and the use of post-quantum cryptographic algorithms based on the Winternitz one-time signatures [7]. On top of that, IOTA firstly introduced its own ternary hashing algorithm, called Curl-P(Prototype). Cryptographic researchers, though, illustrated vulnerabilities in the cryptographic primitives which forced the project to replace the Curl-P function with the peer-reviewed Keccak-384 [48]. Finally, the ternary system makes it considerably harder to assess the protocol for vulnerabilities using well established tools and methodologies [48]. The IOTA foundation claims that most of the vulnerabilities regarding the cryptographic elements have been fixed and are undergoing improvement [49]. Regarding the network, the Coordinator acts as a safety mechanism for the time being, while research is conducted on the consensus algorithms.  
Due to the use of quantum resilient cryptography, IOTA currently has a substantial footprint of 1589 bytes in contrast to Ethereum's 100-110 bytes [17]. In order to assist the IOTA Full Nodes handling the Tangle, the network performs a synchronised snapshot, where all zero-value transactions are deleted and all of the confirmed transactions are reduced to a database. From that point, the Tangle starts growing again until the next snapshot. This poses a considerable problem since all MAM transactions are zero-value and will be deleted at the next snapshot. These apply to IOTA Full Nodes but the IOTA foundation intends to release Permanent Nodes that will store the whole Tangle but will have much greater demands for computational power. An important aspect of future research will be the use of the Tangle as a publicly auditable and immutable \"anchor\" of integrity of data that will be stored off-Tangle in a database.