In an environment wherein a front end system receives a service request, and a back end system responds to the request, a user of a target endpoint must be authenticated. A ticket ID is assigned to the service request, and responsive to an initiating action of the user, a virtual token is generated that has a specified relationship with the ticket ID. The virtual token is delivered to the user, and the user is prompted to present the token to a validating component associated with one of the front end or back end systems, wherein the validating component is configured to verify the token validity. If the token is found to be valid, the user is authenticated to access the specified target endpoint.