@inproceedings{backes06cryptographic,
  author       = {Backes, Michael and Pfitzmann, Birgit},
  title        = {On the Cryptographic Key Secrecy of the Strengthened Yahalom Protocol},
  booktitle    = {Proceedings of 21st IFIP International Information Security Conference (SEC)},
  month        = {May},
  year         = {2006},
  pages        = {233-245}
}