## 6 Evaluation of the Proposed Protocol
### Security Evaluation  
In this section the security comparison is done in the context of secure routing and then of secure data aggregation. We list all possible attacks for each context. We then identify each possible attack that applies in each context based on which security property (data integrity, source authentication, data confidentiality or data freshness, even availability) it attempts to compromise. In evaluating the proposed protocol, we exclude the attacks launched by compromised nodes, or in other words internal attacks are excluded since by design the proposed protocol adopts LEACH-based secure routing and ESPDA that are not equipped to detect compromised nodes or even to punish them. Up until this stage, the proposed protocol does not employ any algorithm (such as witness-based detection to monitor a certain node's behavior, _etc_) to punish compromised nodes. Therefore we do not consider internal attacks launched by compromised nodes. First we evaluate the proposed protocol from the perspective of secure routing, comparing it to its counterparts (SLEACH, SecLEACH and MS-LEACH). In [4], [PERSON] and [PERSON] study the attacks and countermeasures for secure routing protocols in WSN. These attacks are:  
* spoofed, altered, or replayed routing information;
* selective forwarding;
* sinkhole attacks;
* Sybil attacks;
* Wormholes; \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{4}{c}{**Security Requirements**} \\ \cline{2-5}
**Message** & \multicolumn{1}{c}{**Data Integrity**} & \multicolumn{1}{c}{**Source**} & \multicolumn{1}{c}{**Data**} & \\  & & **Authentication** & **Confidentiality** & **Data Freshness** \\ \hline
**adv** & Digital signature & Digital signature & - & Nonce \\
**join\_req** & MAC & Mutual key & - & Nonce \\
**CK\_req** & MAC & Mutual key & - & Counter \\
**CK\_rep** & Digital signature & Digital signature & Encryption & Counter, timestamp \\
**sched\_seed\_permut** & MAC & Cluster key & Encryption & Counter \\
**pattern\_code** & MAC & Mutual key & - & Counter, timestamp \\
**selected\_nodes** & MAC & Cluster key & - & Counter \\
**data** & MAC & Mutual key & Encryption & Counter \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Protocol security requirements fulfillment. * HELLO flood attacks;
* acknowledgment spoofing. The study also presents attacks specific to LEACH-family protocols. These are selective forwarding and HELLO floods attacks. The listed attacks and their descriptions provided in [25] help our evaluation. We filter which attacks are applicable in our context. Those attacks are HELLO floods, selective forwarding, sinkhole attacks, and spoofed/altered/replaying routing information. As we know, a successful launch of a certain attack can lead to the mounting of other attacks. For example, the HELLO floods attack launched by a malicious node may lure many other nodes to join that malicious node's cluster, which later on results in selective forwarding or sinkhole attacks. So we can consider only the HELLO flood attack to simplify our evaluation. Since in LEACH-based secure routing protocols, every node can take a role of either a CH or ordinary node, we consider a node impersonation attack which can be launched to target a CH or ordinary node. If we relate this attack to the previous explained HELLO flood attack, actually the HELLO flood attack is a type of CH impersonation attack since the target here is the CHs. Adversaries may impersonate any legal CH and advertise themselves to the network tricking many other ordinary nodes to join their cluster. This is similar to the HELLO floods attack. Therefore, we use the term CHs impersonation attack to represent HELLO flood attacks in our evaluation. If the node impersonation attack's target is ordinary nodes, then the goal of this attack is to insert false sensor readings. The significant contribution of false sensor readings can obscure the view of the actual network condition. We then add eavesdropping and an attack specific to the LEACH protocol, schedule disruption.