1. Abdelnur, H., Avanesov, T., Rusinowitch, M., State, R.: Abusing SIP Authentication. In: Proceedings of the 4th International Conference on Information Assurance and Security (ISIAS), September 2008, pp. 237–242 (2008)
2. Adelsbach, A., Alkassar, A., Garbe, K.-H., Luzaic, M., Manulis, M., Scherer, E., Schwenk, J., Siemens, E.: Voice over IP: Sichere Umstellung der Sprachkommunikation auf IP-Technologie. Bundesanzeiger Verlag (2005)
3. Anwar, Z., Yurcik, W., Johnson, R.E., Hafiz, M., Campbell, R.H.: Multiple Design Patterns for Voice over IP (VoIP) Security. In: Proceedings of the IEEE Workshop on Information Assurance (WIA), held in conjunction with the 25th IEEE International Performance Computing and Communications Conference (IPCCC) (April 2006)
4. Balasubramaniyan, V., Ahamad, M., Park, H.: CallRank: Combating SPIT Using Call Duration, Social Networks and Global Reputation. In: Proceedings of the 4th Conference on Email and Anti-Spam (CEAS) (August 2007)
5. Barbieri, R., Bruschi, D., Rosti, E.: Voice over IPsec: Analysis and Solutions. In: Proceedings of the 18 th Annual Computer Security Applications Conference (ACSAC), December 2002, pp. 261–270 (2002)