Methods, systems, and apparatus for handling secure-voice-communication sessions

1. A method comprising:

receiving, from a first voice-communication device, a first request to establish a secure-voice-communication session with a second voice-communication device;

receiving, from the second voice-communication device, a second request to establish the secure-voice-communication session with the first voice-communication device;

establishing the secure-voice-communication session between the first and second voice-communication device;

holding the first request until the second request is received; and

after receiving the second request, determining that the second request is associated with the first request.

2. The method of claim 1 , further comprising:

using a base network to handle at least one call-management task associated with the secure-voice-communication session, wherein unsecured-voice-communication sessions with the first voice-communication device are handled by the base network.

3. The method of claim 2 , wherein using the base network to handle at least one call-management task associated with the secure-voice-communication session comprises using the base network to handle at least one setup task for the secure-voice-communication session.

4. The method of claim 2 , wherein using the base network to handle at least one setup task comprises using the base network to handle at least one communication in a registration process for the first voice-communication device.

5. The method of claim 2 , wherein:

the base network comprises a wireless network; and

using the base network to handle at least one call-management task comprises relying on the wireless network to handle at least one mobility-management task.

6. The method of claim 2 , wherein using the base network to handle at least one call-management task comprises relying on the base network to manage presence information associated with the secure-voice-communication session.

7. The method of claim 1 , further comprising terminating an unsecured-voice-communication session in response to the first request, wherein terminating the unsecured-voice-communication session and establishing the secure-voice-communication session are performed in a manner that is transparent to a user of the first voice-communication device.

8. A method comprising:

receiving, from a first voice-communication device, a first request to establish a secure-voice-communication session with a second voice-communication device;

receiving, from the second voice-communication device, a second request to establish the secure-voice-communication session with the first voice-communication device;

establishing the secure-voice-communication session between the first and second voice-communication devices;

using a base network to handle at least one call-management task associated with the secure-voice-communication session, wherein unsecured-voice-communication sessions with the first voice-communication device are handled by the base network;

wherein using the base network to handle at least one call-management task associated with the secure-voice-communication session comprises using the base network to handle at least one setup task for the secure-voice-communication session; and

wherein using the base network to handle at least one setup task comprises using the base network to prompt the second voice-communication device to send the second request.

9. The method of claim 8 , wherein using the base network to prompt the second voice-communication device to send the second request comprises sending a text message to the second voice-communication device over the base network.

10. The method of claim 8 , wherein using the base network to prompt the second voice-communication device to send the second request comprises calling the second voice-communication device over the base network.

11. The method of claim 8 , wherein using the base network to handle at least one setup task further comprises using the base network to handle at least one communication in a registration process for the first voice-communication device.

12. The method of claim 8 , wherein:

the base network comprises a wireless network; and

using the base network to handle at least one call-management task further comprises relying on the wireless network to handle at least one mobility-management task.

13. The method of claim 8 , wherein using the base network to handle at least one call-management task further comprises relying on the base network to manage presence information associated with the secure-voice-communication session.

14. The method of claim 8 , wherein establishing the secure-voice-communication session between the first and second voice-communication devices comprises:

authenticating the first voice-communication device;

authenticating the second voice-communication device;

requesting that a secure-media subsystem provision resources for the secure-voice-communication session;

receiving, from the secure-media subsystem, connection information for the secure-voice-communication session; and

sending security information and the connection information to the first and second voice-communication devices.

15. The method of claim 8 , further comprising terminating an unsecured-voice-communication session in response to the first request, wherein terminating the unsecured-voice-communication session and establishing the secure-voice-communication session are performed in a manner that is transparent to a user of the first voice-communication device.

16. The method of claim 8 , wherein the base network comprises a circuit-switched communication network.

17. The method of claim 8 , tangibly embodied as computer-executable instructions on at least one computer-readable medium.

18. A method comprising:

establishing an unsecured-voice-communication session over a base network;

during the unsecured-voice-communication session, receiving input that initiates a secure-voice-communication session;

terminating the unsecured-voice-communication session;

using the base network to handle at least one call-management task associated with the secure-voice-communication session; and

connecting to the secure-voice-communication session;

wherein using the base network to handle at least one call-management task comprises using the base network to send a secure-application subsystem a first request to establish the secure-voice-communication session; and

wherein the first request indicates that a second voice-communication device should be prompted to send the secure-application subsystem a second request to establish the voice-communication session with a first voice-communication device.

19. The method of claim 18 , wherein using the base network to handle at least one call-management task further comprises using the base network to handle at least one of:

a mobility-management task;

a presence-management task;

a setup task; and

a call-control task.

20. A system comprising:

a secure-session-setup module installed on a secure-application subsystem and programmed to:

receive, from a first voice-communication device, a first request to establish a secure-voice-communication session with a second voice-communication device;

receive, from a second voice-communication device, a second request to establish the secure-voice-communication session with the first voice-communication device; and

establish the secure-voice-communication session between the first and second voice-communication devices; and

a first secure-communication module installed on the first voice-communication device and programmed to send the first request to the secure-application subsystem;

wherein the first request comprises a request to prompt the second voice-communication device to send the second request to the secure-application subsystem.

21. The system of claim 20 , further comprising:

a second secure-communication module installed on the second voice-communication device;

wherein:

the secure-session-setup module is programmed to use a base network to send a communication to the second secure-communication module to prompt the second secure-communication module to send the second request; and

the second secure-communication module is programmed to respond to the communication by sending the second request to the secure-session-setup module.

22. The system of claim 20 , wherein:

the first voice-communication device is configured to use a base network to handle at least one call-management task associated with the secure-voice-communication session; and

unsecured-voice-communication sessions with the first voice-communication device are handled by the base network.

23. A system comprising:

a secure-session-setup module installed on a secure-application subsystem and programmed to:

receive, from a first voice-communication device, a first request to establish a secure-voice-communication session with a second voice-communication device;

receive, from a second voice-communication device, a second request to establish the secure-voice-communication session with the first voice-communication device; and

establish the secure-voice-communication session between the first and second voice-communication devices; and

a secure-media subsystem communicatively coupled to the secure-session-setup module;

wherein:

the secure-session-setup module is programmed to send the secure-media subsystem a request to provision resources for the secure-voice-communication session;

the secure-media subsystem is programmed to respond to the request to provision resources by sending Internet Protocol addresses and ports for the secure-voice-communication session to the secure-session-setup module;

the secure-session-setup module is programmed to send the Internet Protocol addresses and ports for the secure-voice-communication session to the first and second voice-communication devices;

the secure-session-setup module is programmed to create a session key and to send the session key to the first and second voice-communication devices; and

the second voice-communication device is programmed to communicate with the first voice-communication device through the secure-media subsystem.

24. The system of claim 23 , wherein the first voice-communication device is programmed to:

communicate with the second voice-communication device using a secure transport protocol;

receive encrypted voice data from the second voice-communication device; and

decrypt the encrypted voice data.

25. A system comprising:

a secure-session-setup module installed on a secure-application subsystem and programmed to:

receive, from a first voice-communication device, a first request to establish a secure-voice-communication session with a second voice-communication device;

receive, from a second voice-communication device, a second request to establish the secure-voice-communication session with the first voice-communication device;

establish the secure-voice-communication session between the first and second voice-communication devices;

hold the first request until the second request is received; and

after receiving the second request, determine that the second request is associated with the first request.