Local area networks (LANs) have become a major tool to many organizations in meeting data processing and data communication needs. Prior to the use of LANs, most processing and communications were centralized; the information and control of that information were centralized as well. Now LANs logically and physically extend data, processing and communication facilities across the organization Security services that protect the data, processing and communication facilities must also be distributed throughout the LAN. For …showed first 75 words of 297 total…

…showed last 75 words of 297 total…electronic mail messages can be captured and read or perhaps even altered. For some LANs, there can be no assurance that the message actually was sent from the named sender. Fortunately tools such as encryption, digital signatures, and message authentication codes help solve these problems and can help provide some assurance. Understanding the necessity to provide security on a LAN and how to decide the appropriate security measures needed are major goals of this document.