We now know how to guarantee timeliness and, to a lesser extent, how to provide fault-tolerance, on both end systems and their interconnection networks. However, how to secure them is far less known, despite the growing importance of protecting information stored in the end systems/devices and exchanged over their interconnection networks. Morever, timeliness, fault-tolerance, security and privacy---which I call simply QoS---must be supported simultaneously, often with a tight resource budget such as memory, computation and communication bandwidth, and battery power. Also, different applications require different combinations of QoS components, and hence, one-fits-all solutions are not acceptable. This talk will cover issues and approaches to the problems of securing networked embedded systems.