book can have a Trojan horse embedded within it. Some firewalls can also detect anomalies that are indicative of an attack, including packets that are too short. Security Threats from Internal, External, and International Sources Other types of security can be embedded in servers containing applications or installed in a stand-alone appliance (a computer with a dedicated application). There is a trend to embed security in multifunction devices. Routers are often equipped with firewalls, and Local Area Network (LAN) switches also contain optional security software. To prevent hacker attacks, many organizations use Intrusion Detection System (IDS) software or devices to monitor traffic. These systems monitor packets for mal- ware and report them. Intrusion Detection and Prevention Systems (IDPS) attempt to stop these attacks as well as identify and report them. As security programs become more sophisticated, hackers analyze these defenses and build increasingly sophisticated malware to defeat them. It is an ongoing challenge to respond to every new type of security breach with improved defense measures. This is a particularly difficult challenge because there is generally a lag between when a new software bug or worm is discovered and a software patch is created to guard against it. It's also time-consuming to add patches to not only software security but also application programs such as browsers that might also introduce security holes. There is also specialty security for e-mail and other applications. Security soft- ware can be used to encrypt files containing passwords. Encryption is the use of math- ematical algorithms to make files unreadable except to authorized users who have the software necessary to decrypt the files or e-mail messages. Encryption is used also on transmitted files to keep them private. This is important because SO many employees, contractors, and business partners now access files remotely. In addition to all of these practices, firms hire outside organizations to conduct a security audi