This is a big problem. A Real Big
problem.
It can be classified into two broad areas:
Computer security in a networked context. This is the subject
of a later lecture.
Computer systems are subject to attack originating from the
network
Extends well known security approaches adopted for protection
of non-networked systems and adds network-specific mechanisms
No general solutions: any solution which provides perfect
security seriously degrades usefulness of network...
Security of information in transit across the network. This is
the subject of today's lecture.
Problem is largely due to the bad guys' ability to observe
(capture) packets travelling across the network, and possibly an
ability to introduce spurious packets.