The cognitive radio (CR) technique is an encouraging approach to deal with spectrum scarcity in wireless networks. However, this technique raises the issues of secrecy and privacy in the CR network. In this work, a multiple-input multiple-output underlay CR network is considered, which consists of a primary network, a secondary network, and an eavesdropper. All the primary, secondary as well aseavesdropper's nodes are assumed to have multiple antennas with radio frequency energy harvesters to enhance their spectral and energy efficiency properties. The eavesdropper node manipulates it's simultaneous wireless information and power transfer architecture in a pursuit to intercept the secure communication between the cognitive transmitter and the cognitive receiver. This technique and considered network are combined with the traditional selection combining (SC) and maximal ratio combining (MRC) scheme and the results are compared. The Monte Carlo simulation is done for the validation of results. The main aim is to drive the closed-form analytical expression for exact and asymptotic secrecy outage probability. The present results show that the SC scheme at eavesdropper provides better secrecy in comparison to the MRC technique and also the number of antennas affects the secrecy of the system. Moreover, the impact of power splitter is considered and also the optimal value of power splitter is derived to maximize information decoding.Recently essence of connected devices especially in smart cities has given rise to the generation of a large volume of data. However, the spectrum underutilization, scarcity of spectrum, and security are still major issues of concern. The cognitive radio network (CRN) is an encouraging explanation to alleviate the spectrum scarcity and underutilization issue as it increases the spectral as well as energy efficiency. 1 In CRN, the unlicensed users are also known as secondary users (SU) are authorized to access the spectrum without creating any conflict to the licensed users also known as the primary user (PU). 2 The CRN works under underlay, overlay, and interweave mode. 3 Underlay mode is one of the most important components of the CRN where SUs transmit along with the PU by adjusting the transmit power below a threshold point which can be tolerated by the PU. However, the limited battery life of conventional wireless networks is also becoming another bottleneck issue. The duration of a battery can be extended up to a certain limit by charging or replacing the battery but at the cost of increased price and environment degradation. One of the innocuous and greener solutions for energy harvesting (EH) is simultaneous wireless information and power transfer (SWIPT). 4,5 The SWIPT system utilizes Trans Emerging Tel Tech.