https://jjcit.org/paper/74 10.5455/jjcit.71-1563658722 Iman Almomani,Katrina Sundus Authentication,Wireless sensor network (WSN),Security,Mobility,Broadcast authentication,Adaptive window protocol,Authentication first protocol,Forwarding first protocol,Internet of Things (IoT),Digital signature. 6 5932 1879 20-Jul-2019 3-Nov-2019 30-Nov-2019 The applications of Wireless Sensor Networks (WSNs) are very important nowadays and could be found in many different life aspects. Broadcast authentication (BA) protocols are solutions to guarantee that commands and requests sent by the Base Station (BS), which controls the services provided by WSN, are authentic. Network mobility is considered one of the main challenges that WSN services in general and authentication protocols in particular are facing. Existing BA protocols did not give much attention to the effect of mobile BS or/and sensors on the behaviour of their protocols. Consequently, this paper provides a deep analysis of the impact of mobility on the performance of BA protocols. Three standard designs for BA protocols were studied in this research; Forwarding First (FF), Authentication First (AF) and Adaptive Window (AW). These three standard protocols were examined against four major mobility models. The results revealed that BA protocols behaved differently in terms of energy consumption and network delay with respect to mobility. For example, the delay in AW protocol was decreased by 47.6% in case of having fully mobile WSN; whereas the wasted energy was reduced by 37.5% in case of static BS and mobile sensors. Although the same authentication technique was applied in all three protocols, the mobility itself was a reason to enhance or degrade the performance of the authentication service which consequently affects the security of WSNs and their provided services. For example, when the BS was mobile and the sensor nodes were static, FF protocol decreased the delay by up to 98.81% compared to AF protocol and by up to 93.62% compared to AW protocol. On the other hand, AW Protocol saved the network energy by up to 94.49% compared to FF protocol and by up to 65.5% compared to AF protocol.