The design of ubiquitous and embedded computers focuses on cost factors such as area, power-consumption, and performance. Security and trust properties, on the other hand, are often an afterthought. Yet the purpose of ubiquitous electronics is to act and negotiate on their owner’s behalf, and this makes trust a first-order concern. We outline a methodology for the design of secure and trusted electronic embedded systems, which builds on identifying the secure-sensitive part of a system (the root-of-trust) and iteratively partitioning and protecting t-of-trust over all levels of design abstraction. This includes protocols, software, hardware, and circuits. We review active research in the area of secure design methodologies.