USER EXPERIENCE AND METHOD FOR PROMOTING A LOW-ASSURANCE CALL TO A HIGH-ASSURANCE CALL ON A CALLING DEVICE
A low-assurance call on a mobile device to another device may be promoted to a high-assurance call using a user interface. The participants during the call do not need to hang up and start a new high-assurance call. A caller can swipe an icon up a slider, for example, and start a process of promoting the call. The initial low assurance call using SIP servers is terminated but this is transparent to the callers. Once the swipe is performed, a DTLS negotiation is performed between the devices. During this DTLS handshake, which is done directly between the device without involvement of the SIP servers, a key is exchanged. Only the calling devices are aware of this key which is used to encrypt media during the call. Screens on the calling devices show that the call is now high-assurance and security details of the call may also be displayed.
1 . A method of promoting a first-level security call to a second-level security call, the method comprising:
executing the first-level security call between a first mobile device and a second device;
receiving input that the first-level security call is being promoted to a second-level security call;
terminating the first-level security call on the first device and on the second device;
initiating a security negotiation directly between the first device and the second device, wherein only the first device and the second device are involved in the negotiation;
generating a key during the security negotiation, wherein the key is only known to the first device and to the second device; and
initiating the second-level security call using the key to encrypt media in the second-level security call, wherein no external computing devices are utilized.
2 . A method as recited in claim 1 wherein said input results from a caller performing an action on a display of the first device or on the second device.
3 . A method as recited in claim 1 wherein the security negotiation is based on Datagram Transport Layer Security (DTLS).
4 . A method as recited in claim 1 further comprising:
notifying a Session Initiation Protocol (SIP) server when the first-level security call is terminated.
5 . A method as recited in claim 1 wherein initiating a security negotiation further comprises:
displaying on the first device a message that security parameters are being negotiated.
6 . A method as recited in claim 1 wherein initiating the second-level security call further comprises:
changing an icon on the first device and on the second device indicating that the call is second-level security.
7 . A method as recited in claim 1 further comprising:
displaying details of the second-level security call on the first device and on the second device.
8 . A method as recited in claim 1 wherein the first-level security call is a low assurance call and the second-level security call is a high assurance call.
9 . A device for making a voice-over-IP call, the device comprising:
means for executing a first-level security call to a second device;
means for receiving input that the first-level security call is being promoted to a second-level security call, said input resulting from a user action on the device;
means for terminating the first-level security call with the second device;
means for initiating a security negotiation directly with the second device, wherein only the device and the second device are involved in the negotiation;
means for generating a key during the security negotiation, wherein the key is only known to the device and to the second device; and
means for initiating the second-level security call using the key to encrypt media in the second-level security call, wherein no external computing devices are utilized.