Traditional secure registration protocols rely on client‐server authentication procedures. This concept has been extended to support single client registration to multiple servers, using “single sign‐on” protocols. In this paper, we design a framework to solve the “reverse single sign‐on” problem: How can multiple clients securely register with the same server/network in a single registration procedure? The main advantage of our framework is that it allows multiple clients to register with an infrastructure, such as a cellular network, as a “group,” yet generate individual session keys as well as a group session key. With this, the process of authenticating a large number of clients is greatly simplified, thereby dramatically reducing overheads. With a view towards simplifying the exposition, we describe how our framework can be applied for performing group authentication of devices in the machine‐to‐machine context. While this is an immediate area of application, we outline other extensions of the framework in the application layer including webcasting in a social networking environment. © 2012 Alcatel‐Lucent.