A primary purpose of security is to keep intruders out. For most of history,
this meant building strong walls and establishing small, well-guarded doors to
provide secure access for a select group of people. This strategy works better
for wired LANs than WLANs. The rise of mobile commerce and wireless networks
make the old model unsuitable. Security solutions must be seamlessly
integrated, more transparent, flexible, and manageable.
Security usually
refers to ensuring that users can perform only the tasks that they are
authorized to do and can obtain only the information that they are authorized
to have. Security must ensure that users cannot cause damage to the data,
applications, or operating environment of a system. The word security involves
protection against malicious attacks. Security also involves controlling the
effects of errors and equipment failures. Anything that can protect against a
wireless attack will probably prevent other types of trouble as well. The
balance between allowing authorized access and preventing unauthorized access
is illustrated in Figure
.