Emerging information and communication technologies are expected to foster new, efficient and accessible services for citizens, while guaranteeing the core principles of equality and privacy. Telehealth services are a clear example of a service in which technology can help enhance efficiency. The security of telehealth services is essential due to their critical nature. However, although ample efforts have been made to characterize security requirements for healthcare facilities, users are often worried because they are not aware of or do not understand the guarantees provided by the technology they are making use of. This paper describes the concept of User-Centered Security and characterizes it in the form of requirements. These requirements have been formalized in the form of a security architecture that should be utilized for each telehealth service during its design stage. Thus, such sensitive services will adequately manage patient fears regarding their correct operation. Finally, these requirements and the related security architecture have been validated by means of a test-case that is based on a real home telehealth service in order to ensure their consistency, completeness, realism and verifiability.