Implementation of a security system in a local area network environment

The development and the implementation of a security system in a local area network environment are presented. This system is based on an extended Ethernet network, but the methodology used is transferable to different kinds of LCNs and even metropolitan area networks (MANs), with some easy modifications. The adopted solution fulfills all the requirements that must fulfill any security protocol since: it provides cryptographic security services, it is an independent algorithm, it supports transparent operations for protected systems, it does not interfere with the operation of unprotected systems, it provides protocol support of key management independent of data security, and it provides optimal communication with unprotected systems. It also offers advantages such as flexibility, simplicity, low cost, and mobility