Internet of Things (IoT) brings significant challenges to authentication schemes in a scenario with several appliances for a smart house that should be accessed by a technician for maintenance tasks, for instance. An Identity Management (IdM) can be applied to easily authenticate a technician that intend to access the appliances from the Internet. However, Internet context is significantly different from IoT, demanding context adaptation to work. Thus, integrate these contexts to allow the authentication on the Internet and provide Single Sign-On (SSO) in IoT is a challenge. The goal is to allow a technician to access an appliance that is not reachable from the Internet, using IdM and without creating a single compromising point in the gateway that links the two contexts. The proposal interacts two key-based scheme, one for Internet and another for IoT, to reach integration between both contexts. A proof-of-concept implementation shows the proposal is feasible and presents no significant overhead for messages with up to 4096 bytes and 50 appliances.