@inproceedings{PODS-1999-Tygar,
	author        = "J. D. Tygar",
	booktitle     = "{Proceedings of the 18th Symposium on Principles of Database Systems}",
	cdrom         = "DiSC2_1/out/papers/pods/openproblemsinej.pdf",
	doi           = "10.1145/303976.303986",
	isbn          = "1-58113-062-7",
	pages         = "101",
	publisher     = "{ACM Press}",
	title         = "{Open Problems in Electronic Commerce}",
	year          = 1999,
}