## 2 Literature Review  
Researchers have put forth a variety of routing strategies to address the WSN privacy issue with source nodes. In [15; 19; 22; 25; 26; 27; 35; 36], fake packet-based SLP techniques were put out. Since we realized that for energy-constrained WSNs, such schemes (fake packet/fake sources-based SLP) would be energy-expensive, we do not focus on them. Here, we describe only random walk- or phantom routing-based techniques since the proposed scheme falls under this category, as it has been noticed that those techniques are more effective for energy-constrained WSNs [18; 21; 28; 37]. [PERSON] et al. in [23] provide an in-depth review of the source location privacy (SLP) preservation methods suggested for WSN; for more details on this topic, we recommend reading this article. The fundamental goal of employing random walk-based approaches is to make a packet's journey appear entirely random to an adversary in order to defend against hop-by-hop and traffic analysis attacks. As relaying or forwarding nodes are picked at random from a sending node's neighbor set, the packet's journey takes on a random pattern [38]. For the first time, a random walk-based SLP solution was proposed by [PERSON] et al. in [38]. Based on the panda hunter game as the baseline, in order to provide SLP in a WSN, their work introduced the phantom flooding scheme (PFS), which is based on conventional random walks. Every message goes through two phases such as a directed walk phase, followed by a flooding phase that sends the packet to the BS. In the directed walk phase, the packet is relayed for up to H hops in a random manner. Baseline flooding is used to flood the data packet once the hop count H reaches zero. The phantom node (PN) is the node at which the hop count H is zero. This solution showed some degree of privacy. Nevertheless, due to the uneven distribution of packet forwarding probability among neighboring nodes, the attainment of a purely random walk was unsuccessful, resulting in compromised privacy. Additionally, the study failed to consider the improvement in the network lifetime (NLT). Different routing techniques were proposed to improve PFS, including [39; 40; 41]. In [40], the authors proposed a new SLP routing technique, namely, phantom routing with a locational angle (PRLA). The key idea is to forward a packet to the neighbor node that has the greatest inclination angle with reference to the base station. Each node in the network determines the angle of inclination between itself and its neighbors with respect to the base station. Each node then calculates the forwarding probability using that inclination angle. The chance is greatest for the node with the highest angle of inclination. When an event is detected, a node chooses its neighbor with the highest inclination angle and sends the packet to that node. The above procedure continues until the hop count H reaches zero, or if a node cannot transfer the packet to a neighbor node with the required inclination angle, it converts into a phantom node and forwards the packet via shortest path routing to reach the BS. It was observed that this scheme has an enhanced safety period compared to PSF. This is due to the fact that in PSF, tracing back the source of information can be easy since the packet forwarding probability is less evenly distributed among the neighboring nodes of the source of information, as shown in [41; 42; 43]. However, the routing path in this scheme lacks the requisite level of randomness necessary to ensure robust privacy for the source of information, and it also neglects the crucial factor of assessing and improving the network's lifetime. [PERSON] and [PERSON] developed a scheme that uses a three-phase routing strategy [44]. In the first phase, the data packet is sent by the message source to the randomly selected intermediate node (RRIN) in the sensor domain, which subsequently directs it to a ring node. This stage's goal was to offer local source location privacy.