Kevin D. Bowers Lujo Bauer Deepak Garg Frank Pfenning Michael K. Reiter Consumable Credentials in Linear-Logic-Based Access-Control Systems. 2007 NDSS http://www.isoc.org/isoc/conferences/ndss/07/papers/consumable_credentials.pdf conf/ndss/2007 db/conf/ndss/ndss2007.html#BowersBGPR07