Hui Lin, Adam Slagell, Zbigniew Kalbarczyk, and Ravishankar K. Iyer, “Using a Specification-based Intrusion Detection System to Extend the DNP3 Protocol with Security Functionalities,” Coordinated Science Laboratory technical report UILU-ENG-12-2207, the University of Illinois at Urbana-Champaign, November 2012. (paper)