# A Survey on Cybersecurity in IoT
## 4 Network Security and Communication Protocols
### Security Challenges in IoT Protocols  
IoT communication protocols are essential for enabling seamless connectivity and data exchange in IoT ecosystems. However, their design for efficiency and resource-constrained environments often leads to significant security challenges. This section discusses the security issues associated with widely used protocols, including MQTT (Message Queuing Telemetry Transport) [149; 150; 151], CoAP (Constrained Application Protocol) [152; 153; 154], Zigbee [155; 156; 157], and additional protocols such as Bluetooth [158], Z-Wave [159], Lo-RaWAN [160], Thread [161], and Wi-Fi [162]. MQTT, which is widely used in industrial IoT and smart home applications, operates on a publish-subscribe model that, while efficient, is susceptible to several attack vectors, including man-in-the-middle (MitM) attacks [163], replay attacks [164], and unauthorized access due to its default lack of encryption [165]. Although TLS (Transport Layer Security) \begin{table}
\begin{tabular}{p{142.3 pt} p{142.3 pt} p{142.3 pt}} \hline \hline
**Topic** & **References** & **Summary** \\ \hline Advanced & & Discusses traditional and lightweight cryptographic techniques such as hash functions, digital signatures, and homomorphic encryption. Also covers post-quantum cryptography and its applicability to IoT data integrity. \\ \hline Data Integrity in & & Explores methods like SMPC, threshold cryptography, and blockchain technology for maintaining data integrity in distributed IoT systems, particularly in edge computing environments. \\ \hline Privacy & & Focuses on privacy-preserving techniques such as differential privacy and federated learning. Discusses the challenges of implementing these techniques in IoT, especially in scenarios with large-scale data analytics. \\ \hline Privacy in Resource-Constrained Devices & [130; 131; 132; 133; 134; 135; 136; 137; 138; 139; 140] & Analyzes the implementation of privacy-preserving mechanisms in IoT devices with limited resources, including lightweight encryption algorithms and hardware-based security features like TEEs and PUFs. \\ \hline Emerging Threats and Countermeasures & [141; 142; 143; 144; 145] & Identifies emerging threats to data integrity and privacy in IoT, such as AI-based attacks, and discusses potential countermeasures, including AI-driven security solutions and anomaly detection systems. \\ \hline \hline \end{tabular}
\end{table} 
Table 3: A summary of studies related to data integrity and privacy in the IoT. can be layered over MQTT to secure communication, the overhead introduced by TLS can be prohibitive for resource-constrained IoT devices [166]. CoAP, designed for use in lightweight M2M (machine-to-machine) communication, is another protocol that faces security issues due to its reliance on UDP (User Datagram Protocol), which inherently lacks the reliability and security features of TCP (Transmission Control Protocol) [167]. CoAP's use of DTLS (Datagram Transport Layer Security) to secure its communications adds a layer of protection, but challenges such as the proper implementation of DTLS in constrained environments and the potential for DoS attacks remain significant concerns [168; 169]. Zigbee, commonly used in wireless sensor networks and smart home applications, operates on the IEEE 802.15.4 standard and uses AES-128 for encryption. Despite this, Zigbee networks have been shown to be vulnerable to attacks such as key extraction, traffic analysis, and device impersonation. The open nature of the Zigbee protocol stack, while beneficial for interoperability, also exposes it to a wide range of potential security threats [170; 171; 172]. Bluetooth, particularly Bluetooth Low Energy (BLE), is widely used in wearable devices and short-range IoT systems. Although BLE improves energy efficiency, it remains vulnerable to attacks like eavesdropping, replay attacks, and unauthorized device pairing. Enhanced authentication mechanisms and the adoption of Secure Simple Pairing (SSP) protocols can improve security in Bluetooth-based IoT applications [173; 174].