@inproceedings{backes03intransitive,
  author       = {Backes, Michael and Pfitzmann, Birgit},
  title        = {Intransitive Non-Interference for Cryptographic Purposes},
  booktitle    = {Proceedings of 24th IEEE Symposium on Security and Privacy},
  month        = {May},
  year         = {2003},
  pages        = {140-152}
}