The recent advancement of wireless-based communication technology and electronics has facilitated the implementation of a low-cost, low-power sensor network. Basically, a ubiquitous sensor network (USN) consists of three parts: a sensor network consisting of a large number of sensor nodes, a base station (also known as a gateway) interfacing between the sensor networks and an application server, and the application server controlling the sensor node in the sensor network or collecting the sensed information from the sensor nodes in the sensor network. USN can be an intelligent information infrastructure of advanced e-Life society, which delivers user-oriented information and provides knowledge services to anyone anytime, anywhere and wherein information and knowledge are developed using context awareness by detecting, storing, processing, and integrating the situational and environmental information gathered from sensor tags and/or sensor nodes affixed to anything. Since there are many security and privacy threats in transferring and storing information in the USN, appropriate security mechanisms may be needed to protect against those threats in the USN. This Recommendation | International Standard describes the security threats to and security requirements of the ubiquitous sensor network. In addition, this Recommendation | International Standard categorizes the security technologies according to the security functions that satisfy the said security requirements and where the security technologies are applied in the security model of the USN. Finally, the security requirements and security technologies for the USN are presented.