# The Security Perspectives of Vehicular Networks: A Taxonomical Analysis of Attacks and Solutions
## 3 Classification of Attacks in VANETs
### Classification Based on Attacker Type  
In vehicular networks, there may be different kinds of attackers that may launch an attack using different methods [11; 66]. VANET attackers may be classified as follows. Basic attacker categories are active and passive attackers. Active attackers are those who actively take part in the attack, while on the other hand, passive attackers, which are considered relatively less harmful, don't participate actively in the attack and just monitor the information. Additionally, we can classify them as internal and external attackers. These attackers are also known as insider and outsider attackers. Internal attackers are part of the network and they have full information about the network, but external attackers are  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Attacked Layer** & **Type of Attack** & **Reference(s)** \\ \hline \multirow{4}{*}{Confidentiality} & Man-in-the-middle attack & [PERSON] et al. (2018) [42], [PERSON] et al. (2012) [43] \\ \cline{2-3}  & Traffic analysis attack & [PERSON] et al. (2008) [44] \\ \cline{2-3}  & Social attack & [PERSON] et al. (2011) [45] \\ \cline{2-3}  & Eavesdropping attack & [PERSON] et al. (2019) [46] \\ \hline \multirow{4}{*}{Integrity} & Masquerading attack & [PERSON] et al. (2016) [47] \\ \cline{2-3}  & Replay attack & [PERSON] et al. (2018) [48], [PERSON] et al. (2019) [49] \\ \cline{2-3}  & Message tampering attack & [PERSON] and [PERSON] (2019) [50] \\ \cline{2-3}  & Illusion attack & [PERSON] and [PERSON] (2007) [51] \\ \hline \multirow{4}{*}{Availability} & DoS/DDoS & [PERSON] et al. (2014) [52], [PERSON] et al. (2012) [53] \\ \cline{2-3}  & Sleep deprivation & [PERSON] et al. (2012) [54] [PERSON] et al. (2017)[55] \\ \cline{2-3}  & Jamming attacks & [PERSON] et al. (2017) [55], [PERSON] et al. (2014) [56] \\ \cline{2-3}  & Jellyfish attack & [PERSON] et al. (2012) [54], [PERSON] et al. (2017) [57] \\ \cline{2-3}  & Intelligent cheater attack & [PERSON] et al. (2017) [57] \\ \cline{2-3}  & Blackhole attack & [PERSON] and [PERSON] (2013) [58] \\ \cline{2-3}  & Grayhole attack & [PERSON] et al. (2007) [59] \\ \cline{2-3}  & Greedy behaviour attack & [PERSON] et al. (2014) [60] \\ \cline{2-3}  & Spamming attack & [PERSON] et al. (2011) [45] \\ \hline \multirow{4}{*}{Authenticity} & [PERSON] attack & [PERSON] et al. (2015) [61], [PERSON]. (2002) [62] \\ \cline{2-3}  & Tunnelling attack & [PERSON] et al. (2019) [63] \\ \cline{2-3}  & GPS spoofing & [PERSON] et al. (2020) [41] \\ \cline{2-3}  & Free-riding attack & [PERSON] et al. (2015) [64] \\ \cline{2-3}  & Certificate/key replication attack & [PERSON] et al. (2018) [48] \\ \hline Non-repudiation & Repudiation attack & [PERSON] et al. (2014) [65] \\ \hline \hline \end{tabular}
\end{table}
Table 1: Attack classification based on security services.  
not part of the network and do not have any kind of information about network structure. Another classification can be malicious and rational attackers. Rational attackers are those who launch an attack for the sake of money or some other personal reason like revenge, and malicious attackers on the other hand launch attacks without having any personal benefits. Furthermore, some other categories can also exist. Timing attacker modifies the timing involved in communication or inserts unnecessary delays in the communication [67]. Communication attacker selects a particular type of communication like V2V or V2I as a target and launches an attack against the VANET systems. Area attacker launches an attack on a specific vehicle or set of vehicles or on specific areas with some predetermined objectives.