A method and system for establishing a secure device-to-device connection between two mobile devices involves the use of a WiFi Direct (LTE Direct or other similar protocols) link paired with an IP Multimedia Subsystems (IMS) link. A device detects the presence of another device that it wishes to connect to. The devices negotiate a group owner, then authenticate each other using a variety of techniques, such as a centrally issued certificate. Thereafter, the devices derive keys to be used for communication, both over the WiFi Direct link and via the IMS link. A WiFi Direct Link may be paired with a Push to Talk over Cellular (PoC) link in order to couple together more than two devices. In such a connection, devices transmit to a group owner, which then sends multicast versions to the rest of the group devices.