This volume contains the papers presented at the Third International Conference on Security in Pervasive Computing (SPC 2006), held April 19 21, 2006 in York, UK. The conference focused on methods, tools, principles, and practices for assessing and achievingsecurityinapervasiveenvironment.Newsecurityconceptswerediscussed, in domains and applications such as handheld devices, mobile phones, smartcards, RFID chips, and smart labels, as well as new, emerging technological spaces. The conf- ence also presented work on fundamental themes such as risk identi?cation and mi- gation, security policies...