1. P. Zimmermann, A. Johnston, and J. Callas, “ZRTP: Media Path Key Agreement for Secure RTP”, draft-zimmermann-avt-zrtp-09 (Internet-Draft), Internet Engineering Task Force, September 2008.
2. J. Rosenberg, H. Schulzrinne, G. Camarillo, A. Johnston, J. Peterson, R. Sparks, M. Handley, and E. Schooler, “SIP: Session initiation protocol,” RFC 3261 (Proposed Standard), June 2002. [Online]. Available: http://www.ietf.org/rfc/rfc3261.txt.
3. M. Baugher, D. McGrew, M. Naslund, E. Carrara, and K. Norrman, “The Secure Real-time Transport Protocol (SRTP),” RFC 3711 (Proposed Standard), Mar. 2004. [Online]. Available: http://www.ietf.org/rfc/rfc3711.txt.
4. M. Petraschek, T. Hoeher, O. Jung, H. Hlavacs, and W. Gansterer, “A man-in-the-middle attack on ZRTP,” in Workshop on Socio-Economic Issues of NGI, Santander, Spain, 2007.
5. P. Zimmermann, A. Johnston, and J. Callas, “ZRTP: Media Path Key Agreement for Secure RTP,” draft-zimmermann-avt-zrtp-09 (Internet-Draft), Internet Engineering Task Force, September 2008.