James Michael Stewart, Security+, CISSP, CEH, CHFI, is asecurity expert, full-time writer, trainer, and researcher forImpact Online, an independent courseware development company. Hehas authored and contributed to over 75 books, including previouseditions of the CompTIA Security+ Review Guide, and theCISSP Study Guide, both by Sybex. Stewart provides ITinstruction across the globe for various public and privateorganizations.