This piece is a 14-page, 7-source introduction to the network security technology known as IPSec. IPSec is an open standard for IP security and uses several protocols and algorithms to provide a customizable, robust security system for system administrators. The various applications, protocols and algorithms are discussed, followed by a brief discussion of how the technology works. Then, the advantages of IPSec, including e-commerce and mobile computing, are discussed briefly. A table of contents is included to make navigating the headings and subheadings easier. 14 pgs. Bibliography lists 7 sources.