Wireless Sensor Networks (WSNs) is a very attractive technique to support Ubiquitous Pervasive Computing (UPC) due to many merits such as compact form, low-power, and potential low cost. However, the more the number of sensor node is increased, the more difficult the manager monitors WSNs individually. And faults of the sensing value are common due to the artificial attacker and the lack of physical protection. Therefore, we propose a key management and distributed abnormal area scanning scheme using spatial, temporal correlation and in-network aggregation for secure UPC. Simulations show that our scheme can clearly identify the abnormal sensors with high accuracy even in the existence of normal sensors, abnormal sensor, and event-detecting sensors. In addition, we show that the delivery ratio is increased under various network environments through the key management scheme.