# IoT Blockchain Data Vercity with Data Loss Tolerance
## 1 Introduction
Data-driven productivity improvement with IoT requires appropriate strategies in addressing the data losses. Hence, this research has explored various solutions in circumventing the data loss problem. The solution must ensure the data veracity of IoT  
Figure 1: Complex combination of agro-climatic conditions. data captured even in the absence of consistent infrastructure resources. In this research, the problem of data loss is addressed by an IoT data loss avoidance with blockchain's peer-to-peer (P2P) network and secured distributed storage (DLT). Instead of storing the captured data in an individual sensor, the data is to be stored in a secured distributed storage architecture. It records transactions captured by peer nodes, and securely stores them in distributed peer nodes with no single-point-of-failure (Figure 2). In general, the transacted data are hashed, verified and stored in distributed nodes based on a pre-agreed consensus mechanism [6]. Table 1 gives a brief description of blockchain generation. The first generation of blockchain is based on the Proof-of-Work (PoW) algorithm and is used in cryptocurrencies without the need of a centralized authority. This not only reduces risk but also eliminates extensive processing and transaction overhead. The second generation of blockchain has wider functionality, and is capable of processing smart contracts and decentralized applications. The third generation is enhanced with higher scalability, higher speed of transactions, and consumes less energy. It was extended to various domains like governance and education. The fourth generation is related to the Industrial Revolution (IR) 4.0, which is named Blockchain 4.0. Blockchain is an evolving technology that we anticipate will address the existing shortcomings in IoT data veracity. Blockchain distributed ledger technology is seen as an innovative approach to secured data storage with high availability even in the scarce infrastructure resources environment. It is envisaged that data veracity can be realized with blockchain technology. Data veracity in the blockchain context means to guarantee that the transaction data is accurate, complete, and highly available in ensuring single-source-of-truth. As depicted in Figure 2a, in conventional agricultural IoT, data captured are stored in individual sensor devices. Inevitable device failures might cause data loss. However, with the introduction of blockchain technology in Figure 2b, devices are inter-connected in a P2P network and transacted data are stored in secured distributed nodes. There is no single-point-of-failure situation, as transacted data are secured as they are replicated over the entire IoT blockchain and shall survive any device failure. The IoT blockchain data veracity can be further enhanced with a proper monitoring system. The data veracity monitoring is considered absolutely important for IoT blockchain \begin{table}
\begin{tabular}{c c} \hline \hline
**Generation** & **Application and Usage** \\ \hline
1 & Cryptocurrency and Bitcoin. Mainly used in financial applications. \\
2 & Introduced the concept of smart contracts and made possible the digital \\  & tokenization of physical assets.Usage confined to financial applications. \\  & Enhanced with lower processing cost and speed of transactions. Relatively \\
3 & more matured decentralized application compared to previous G1 and G2, \\  & extended to non-financial domains like governance and education. \\
4 & Enabling more applications through easy-to-consume application interface. \\  & Related to Industry Revolution 4.0 application. \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Blockchain generations and main applications. Figure 2: Conventional vs. Blockchain-based IoT architecture with respect to data loss. (**a**) Conventional IoT with potential data loss. (**b**) Blockchain-based IoT without data loss. data veracity. Premature failure can be detected and trigger rapid corrective action to mitigate any potential data loss situation.