# Blockchain Based Secure Routing and Trust Management in Wireless Sensor Networks +
## 2 Related Work
### Data Storage
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Problems** & **Already** & **Solutions** & **Already** & **Validations** & **Already Done** & **Problems to be Addressed** & **C1** & **C2** & **C3** \\ \hline \hline \multirow{3}{*}{Incorrect location estimation and energy dissipation} & Node’s trust values are based on data based and behavioral based trust [10] & False Positive Rate (FPR), Detection Accuracy (DA), False Negative Rate (FNR), localization error, energy consumption & Malicious node detection consumes high computational cost. Due to indirect trust evaluation, nodes act maliciously & \(\checkmark\) & \(\times\) & \(\times\) \\ \hline \hline \multirow{3}{*}{Existing models do not allow content access, reliable authentication and trust management} & Blockchain authentication and trust module attains authentication and trust via digital signature [18] & \multirow{3}{*}{N/A} & Weak hashing algorithm. Poor authentication, malicious nodes tamper with the data & \multirow{3}{*}{\(\checkmark\)} & \multirow{3}{*}{\(\times\)} & \multirow{3}{*}{\(\times\)} \\ \cline{1-1} \cline{5-5}  & BTM for malicious node detection is proposed data fairness & Security, traceability and reliability analysis & Security, traceability and reliability analysis & PoW requires high energy and faster computer processing to solve cryptographic puzzles that make it costly & \(\times\) & \(\checkmark\) & \(\times\) \\ \hline \multirow{3}{*}{SNs captured by malicious nodes broadcast inaccurate localization & Range free algorithm is proposed for secure localization [20] & Average localization error, localization error variance & Large communications overhead, consumes more energy due to the dynamic behavior of SNs & \(\times\) & \(\checkmark\) & \(\times\) \\ \hline \multirow{3}{*}{Security threats arise in IoT platform} & IoT authentication protocol based on the blockchain is proposed [24] & N/A & \multirow{3}{*}{N/A} & Sink nodes do not authenticate the SNs at the time of assigning sequence numbers & \multirow{3}{*}{\(\checkmark\)} & \multirow{3}{*}{\(\times\)} & \multirow{3}{*}{\(\checkmark\)} \\ \cline{1-1} \cline{5-5}  & Dynamic WSN has more uncertainty and a large coverage area, which causes trust issues & Registration of nodes, cluster formation and node layout [25] & Forward and backward sector formation and node group consumption & Complexity increases in key management. Communication overhead between BS and high storage space sensors & \multirow{3}{*}{\(\times\)} & \multirow{3}{*}{\(\checkmark\)} \\ \cline{1-1} \cline{5-5}  & Lack of traceability of each node in the IoT network & IoT framework is proposed where tractability of each node requires nodes’ registration into the blockchain [26] & Probability of attack success, authentication accuracy & Requires extra maintenance cost and storage capacity. Data tampering in local database & \multirow{3}{*}{\(\times\)} & \multirow{3}{*}{\(\checkmark\)} & \multirow{3}{*}{\(\checkmark\)} \\ \hline \hline \multirow{3}{*}{Secure socket layer does not ensure user anonymity} & The proposed system ensures data authenticity using blockchain to store data [27] & Power consumption, temperature, humidity measurement & N/A & \(\checkmark\) & \(\times\) & \(\times\) \\ \hline \end{tabular}
\end{table} 
Table 1: Literature review.