The Personal Cloud paradigm has recently emerged as a way to allow individuals to manage under their control the collection, usage and sharing of data in different contexts and for different types and sensitivities of data. While much research work is tackling the organisation and semantic exploitation of the user's workspace, far less attention has been paid to security issues. We promote a new approach, called Secure Personal Cloud, where the root of security is made of secure hardware and the access control policies are easily extracted from the personal cloud itself, with minimal user interaction. Our solution is based on the tight integration of a Personal Cloud platform (Cozy) with a trusted component (PlugDB).