Consider the case of key escrow

The key used to encrypt the media or the signaling can be escrowed with another party (either inside the same organization or outside of it)

However, given a session key - content (the media in the call) could later be generated which the parties to the call would have a hard time denying (i.e., the content could be fabricated).

Slide Notes

Md. Sakhawat Hossen, A Session Initiation Protocol User Agent with Key Escrow:Providing authenticity for recordings of secure sessions, Masters thesis, KTH, ICT/COS, TRITA-ICT-EX-2010:1,January 2010
Muhammad Sarwar Jahan Morshed, Voice over IP and Lawful Intercept: God cop/Bad cop, Masters thesis, KTH, ICT/COS, TRITA-ICT-EX-2010:28, February 2010.
Abdullah Azfar, Multiple Escrow Agents in VoIP, Masters thesis, KTH, ICT/COS, TRITA-ICT-EX-2010:109, June2010,

Transcript

[slide404] We'll say something now about key escrow, how it works.