[Chen95] S. Stanniford-Chen and L. Heberlein, Holding Intruders Accountable on the Internet, Proceedings of the 1995 IEEE Symposium on Security and Privacy, 1995, pp39-49. [This paper describes a method for fingerprinting packet content to trace individual behaviors back through networked connections. It is unable to trace back through connections using cryptography and is only an experimental idea at this time.]