Our look is the result of reader comments, our own experimentation, and feedback from distribution channels. Distinctive covers complement our distinctive approach to technical topics, breathing personality and life into potentially dry subjects.

The animals on the cover of Network Security Assessment are porcupine fish (Diodon hystrix). This fish is found in oceans throughout the world, most often among or near coral reef areas. Its tube-shaped body ranges in length from 3 to 19 inches with relatively small fins. When threatened, the fish inflates itself by taking in tiny gulps of water until the stomach is full; the body expands in seconds to double or triple size, and its spines become erect. (Smaller species have spines that are permanently bristly.) The porcupine fish is covered with evenly spaced dark spots, which distinguishes it from other puffers.

The fish has a a single tooth in each jaw; fused at the midline, they form a parrotlike beak. A nocturnal hunter, it moves its body over a small area of sand and spurts tiny jets of water to uncover its prey, usually mollusks and crustaceans. The porcupine fish is popular as an aquarium specimen; it's also blown up, dried, and sold as a souvenir.

In earlier centuries, certain Pacific island warriors used the porcupine fish to fashion a battle helmet. They would catch a fish, let it inflate, and then bury it in sand for about a week. When dug up, the fish, now a hard ball, would be cut open to make a hard, head-shaped piece that looked most formidable. The porcupine fish isn't listed as endangered or vulnerable with the World Conservation Union.

Mary Anne Weeks Mayo was the production editor and proofreader, and Derek DiMatteo was the copyeditor for Network Security Assessment. Reg Aubry and Claire Cloutier provided quality control. Jamie Peppard, Mary Agner, and Marlowe Shaeffer provided production assistance. Julie Hawks wrote the index.

Emma Colby designed the cover of this book, based on a series design by Edie Freedman. The cover image is a 19th-century engraving from the Dover Pictorial Archive. Emma produced the cover layout with QuarkXPress 4.1 using Adobe's ITC Garamond font.

The online edition of this book was created by the Safari production group (John Chodacki, Becki Maisch, and Madeleine Newell) using a set of Frame-to-XML conversion and cleanup tools written and maintained by Erik Ray, Benn Salter, John Chodacki, and Jeff Liggett.