# Reliable Internet of Things: Challenges and Future Trends
## 5 Review of Recent Work in Literature on Reliable Data Transmission in IoT
### Security  
Security is an important requirement for reliable data transmission in IoT. Techniques that provide defense against malicious users and their attacks are required to ensure reliability in IoT. As shown in Figure 5, security techniques include cryptography techniques, blockchain-based techniques and data integrity detection techniques. In Table 6, we provide the recent work related to security in IoT. The work in [126] proposes an anomaly detection technique for IoT devices. The proposed security algorithm is implemented at edge gateways and classifies traffic as abnormal and normal. The classification is done using fuzzy C-means clustering and fuzzy interpolation. Once the anomaly is detected, access to the malicious IoT nodes is \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Scenario** & **C** & **B** & **D** & **Key Idea** & **Results** \\ \hline \multirow{3}{*}{Anomaly detection at edge gateways [126]} & \multirow{3}{*}{✗} & \multirow{3}{*}{✗} & \multirow{3}{*}{✓} & \multirow{3}{*}{✓} & Classify traffic as anomalous and normal based & Improved accuracy \\  & & & & Fuzzy C-means clustering \& fuzzy interpolation & Reduced false positive rate \\ \cline{5-5}  & & & & & Access to malicious IoT nodes restricted & \\ \hline \multirow{3}{*}{Transport layer security for IoT applications [127]} & \multirow{3}{*}{✓} & \multirow{3}{*}{✗} & \multirow{3}{*}{✗} & Reduce latency and achieve forward secrecy & \multirow{3}{*}{Reduced latency} \\  & & & & Identity-based cryptographic technique & & Reduced traffic overhead \\ \cline{5-5}  & & & & Identity-based encryption for client-server data & \\ \hline \multirow{3}{*}{Secure 5G Internet of drones [128]} & \multirow{3}{*}{✗} & \multirow{3}{*}{✓} & \multirow{3}{*}{✗} & Blockchain for secure transmission & \multirow{3}{*}{Robustness against attacks} \\  & & & & Private blocks \& Transactions are recorded & \\ \cline{5-5}  & & & & Novel consensus algorithm is developed & \\ \hline \multirow{2}{*}{IoT insider attacks [129]} & \multirow{2}{*}{✗} & \multirow{2}{*}{✗} & \multirow{2}{*}{✓} & \multirow{2}{*}{✓} & Malicious attack detection from IoT insiders & Improved accuracy \\  & & & & AI and distance based attacks classification & Reduced computation time \\ \hline \multirow{2}{*}{AES for constrained IoT devices [130]} & \multirow{2}{*}{✓} & \multirow{2}{*}{✗} & \multirow{2}{*}{✗} & Reduce complexity of the standard AES algo. & \multirow{2}{*}{Reduced encryption time} \\  & & & & Use a reduced number of rounds for algorithm & \\ \cline{5-5}  & & & & Mathematical proof of proposed protocol & \\ \hline \multirow{3}{*}{Data Integrity attacks in IoV [131]} & \multirow{3}{*}{✗} & \multirow{3}{*}{✗} & \multirow{3}{*}{✓} & Isolation forest algorithm used & \multirow{3}{*}{Improved anomaly detection accuracy} \\  & & & & Find anomalies in traffic density information & \\ \cline{5-5}  & & & & Detected anomalies verified & \\ \cline{5-5}  & & & & Verification from the neighborhood area & \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Security in IoT: Recent literature review (C = Cryptographic Technique, B = Blockchain, D = Data Integrity Attack Detection). Figure 5: Different categories of recent work in Security in IoT. restrictedThe results signify the performance of the proposed protocol in terms of improved accuracy of anomaly detection and reduced false-positive rate. In [127], the authors proposed a transport layer security protocol for IoT applications. The goal is to reduce the latency and achieve forward secrecy. In this regard, an identity-based cryptographic technique is proposed. The key idea is that the client uses identity-based encryption to transmit data to the server when it receives no response from the serverThe results show reduced latency and reduced traffic overhead. The work in [128] proposes a secure communication technique for 5G Internet of drones. Blockchain technology is used to ensure secure data transmission. Private blocks are created, and transactions are recorded in them. Moreover, a novel consensus algorithm is also developed.