###### Abstract  
This paper proposes a routing protocol for wireless sensor networks to deal with energy-depleting vampire attacks. This resource-conserving protection against energy-draining (RCPED) protocol is compatible with existing routing protocols to detect abnormal signs of vampire attacks and identify potential attackers. It responds to attacks by selecting routes with the maximum priority, where priority is an indicator of energy efficiency and estimation of security level calculated utilizing an analytic hierarchy process (AHP). RCPED has no dependence on cryptography, which consumes less energy and hardware resources than previous approaches. Simulation results show the benefits of RCPED in terms of energy efficiency and security awareness.  
energy efficiency; resource depletion attack; secure routing; wireless sensor network +
Footnote †: journal: Network  
0000-0001-5000-5000-5000]Thomas M. Chen  
0000-0001-5000-5  
for sensor nodes in specific WSN applications. Vampire attacks can cause those sensors to stop functioning sooner than normal, which can cause disruptions for the network. Thus, network operators must detect abnormal signs of vampire attacks and identify potential attackers.  
Vampire attacks can carry out the following:  
* Route loop attack (carousel attack): In this attack mode, the adversary intentionally creates routing loops and repeatedly makes data packets travel over the same loop.
* Stretch attack: In this attack mode, the adversaries try to stretch the length of regular routes as much as possible and make data pass through as many unnecessary nodes as possible. Consequently, the average route length may increase noticeably, and so does the number of nodes initially not supposed to be involved in data transmission.  
Vampire attacks are inclined to secretly damage the network by small increments rather than generating vast data to paralyze the network promptly. Since data transmissions will be accomplished at the end of the day (but with much higher costs in resources), it is difficult for network operators to detect and prevent vampire attacks. To the best of our knowledge, there have been very few studies on defense against vampire attacks. On the other hand, existing solutions rely on cryptographic operations, which require considerable computational power and energy consumption from sensor nodes with limited resources.  
Later in this paper, we investigate how to protect routing protocols from vampire attacks in a more energy-efficient manner (this paper also serves as part of the first author's Ph.D. thesis [14]). The proposed work provides energy-efficient routing protection by collaborating with existing routing protocols. The protection is independent of cryptography, consuming less energy and hardware resources. This advantage is significant to sensors in WSNs as they are usually in possession of very limited energy storage and computational capability. The rest of this paper is organized as follows: In Sections 3-5, the detection of vampire attacks is described in detail. Section 5 discusses how to mitigate harm from vampire attacks. Performance evaluation of the proposed solution in terms of simulation results is presented in Section 6.