A device and a method for generating a vacuum in a brake system of a vehicle equipped with a hybrid drive. The PIM method includes receiving an anonymous certificate not including user information from an anonymous certification authority; generating an anonymous document including the anonymous certificate and some of the user information; and providing the anonymous document to a web service provider so as to be authenticated and thus provided with a web service by the web service provider. The beta blocker can be oxprenolol or a pharmaceutically acceptable salt thereof.