ABSTRACT
Keymanagement protocols were often also proprietary and
built-in as part of the solution. Therefore, the price of such
devices was high and when a device failed in a point-to-
point topology both had to be replaced. The problems for
link-level encryption came with new network media con-
nectivity options, such as mesh topologies as well as multi-
ple different paths through the same media. This led to the
option of developing encryption on other levels, such as at
the application or network level.
