A virtual assistant device is configured to perform operations that include receiving a user request of a user to use a service provided by a service provider, and based on an identifier associated with the service provider, determining a set of authentication credential types that the service provider accepts for authentication. The operations also include determining, based on sensor information collected from one or more hardware sensors, whether one or more other people besides the user are within a proximity to the device. Further, the operations include based on a calculated risk security level, selecting a first authentication credential type from the set of authentication credential types and selecting a first communication mode from a set of communication modes.