Quality and security are two intertwined concepts where quality seeks perfection while security countermeasures the elements which weakens the quality. Wireless sensor networks have emerged as a promising future of many sensitive applications. Due to the wireless media and the deployment nature, sensor networks are more prone to security attacks. Several security solutions have been proposed, mostly adding overheads to already resource limited sensor networks. Delivering security and quality simultaneously is challenging because security mechanism severely affects quality mechanisms in terms of performance, data confidentiality, availability, integrity and authentication. This paper presents a Quality of Security (QoSec) concept through a triple key scheme (TKS) which has comparatively low security overheads hence providing a quality security solution against the known attacks in wireless sensor networks. Three metrics; time to transmit, latency overheads and energy overheads are used to do comparative analysis with other existing solutions. Experimental results show that triple key scheme (TKS) has low overheads hence delivering a quality security at low computational cost.