Brinda Dalal Les Nelson Diana K. Smetters Nathaniel Good Ame Elliot Ad-hoc Guesting: When Exceptions Are the Rule. 2008 UPSEC http://www.usenix.org/events/upsec08/tech/full_papers/dalal/dalal.pdf conf/nsdi/2008upsec db/conf/nsdi/upsec2008.html#DalalNSGE08