The authors, Anoop Singhal and Karen Scarfone of the National Institute of Standards and Technology (NIST) and Theodore Winograd of Booz Allen Hamilton, wish to thank their colleagues who contributed technical content to this document, especially Holly Lynne McKinley, Patrick Holley, and Karen Mercedes Goertzel of Booz Allen Hamilto n. The authors would like to acknowledge Tim Grance, David Ferraiolo, and Rick Kuhn of NIST, Jeremy Epstein of Web Methods and David Kleiner, Michael Colon, Steven Lavenhar, and Victoria Thompson of Booz Allen Hamilton, for their keen and insightful assistance throughout the development of the document. n. The authors would like to acknowledge Tim Grance, David Ferraiolo, and Rick Kuhn of NIST, Jeremy Epstein of Web Methods and David Kleiner, Michael Colon, Steven Lavenhar, and Victoria Thompson of Booz Allen Hamilton, for their keen and insightful assistance throughout the development of the document.