# Attack Classification Schema for Smart City WSNs
## 2 Background and Related Work
### Wireless Sensor Networks
#### 2.2.2 WSN Security  
The constrained capabilities of WSNs nodes in terms of processing power and battery are the main obstacle in deploying standard protection mechanisms and in logging security events in the nodes. Therefore, this technology is usually considered to be easy to attack. In [15; 16], the authors survey the most popular attacks on WSNs, and they also describe several countermeasures to prevent them. Table 1 lists the most popular attacks and shows the basic information security principles (i.e., data confidentiality, integrity availability and non-repudiation) that can be compromised by the attacks.  
Figure 2: WSN communication topologies.  
Many researchers have proposed countermeasures embedded in the sensor nodes to prevent most of the attacks shown in Table 1[15; 16]. In this context, adequate embedded algorithms not only have to improve network security, but also have to consider the energetic constraints of the WSNs. Aware of this fact, researchers propose security and fault-tolerant mechanisms having energy efficiency as an additional requirement. For instance, [17] proposes a low energy consuming mechanism to select the most trustworthy cluster head for cooperative spectrum sensing environments. In [18], the authors increase the reliability in mesh networks by reconstructing a reduced amount of broken links in order to recompute faulty paths. The authors claim that the proposed algorithms use less control packets and are more energy efficient than other comparable solutions. In [19], the authors propose a secure multipath routing scheme, which is tolerant to faults and intrusions, and it also preserves the energy of the sensors.  
Although these techniques are recommendable and should be implemented by the WSN providers, they cannot be considered as a security solution that smart city administrators can use to successfully manage WSN security in a holistic and generalizable manner. Indeed, the available security protocols are only applicable to certain technologies with specific requirements. For this reason, smart city  
\begin{table}
\begin{tabular}{l|l} \hline \hline \multicolumn{2}{c}{**Physical Layer**} \\ \hline
**Attack** & **Compromised Principles** \\ \hline Data tampering & Integrity \\ Node tampering & Confidentiality, integrity, availability \\ Node replication & Integrity \\ Jamming & Availability \\ \hline \multicolumn{2}{c}{**Data Link Layer**} \\ \hline
**Attack** & **Compromised Principles** \\ \hline Sybil & Integrity, availability \\ Interrogation & Availability \\ Exhaustion & Availability \\ Collision & Availability \\ Unfairness & Availability \\ \hline \multicolumn{2}{c}{**Network Layer**} \\ \hline
**Attack** & **Compromised Principles** \\ \hline Sleep deprivation & Availability \\ Internet smurf & Integrity, availability \\ Misdirection & Availability \\ Acknowledgment spoofing & Integrity, availability \\ Spoofed, altered, or & Integrity, availability \\ replayed routing information & Integrity, availability \\ Wormhole & Availability \\ Sybil & Integrity, availability \\ Selective forwarding & Availability \\ and black hole & Availability \\ Hello flood & Availability \\ Sinkhole & Availability \\ Homing & Confidentiality \\ \hline \multicolumn{2}{c}{**Transport Layer**} \\ \hline
**Attack** & **Compromised Principles** \\ \hline De-synchronization & Integrity, availability \\ Flooding & Availability \\ \hline \multicolumn{2}{c}{**Application Layer**} \\ \hline
**Attack** & **Compromised Principles** \\ \hline Deluge & Integrity \\ Path-based DoS & Availability \\ Overwhelm & Availability \\ Eavesdropping & Confidentiality \\ Re-play & Non-repudiation \\ \hline \hline \end{tabular}
\end{table}
Table 1: Information security principles compromised by WSN attacks.  
administators should approach security from a wider perspective and take into account intrusion detection techniques in order to analyze WSN data received from the providers and verify that the networks are operated correctly.