For example if an attacker can only access the system

This preview shows page 24 - 36 out of 36 pages.

For example, if an attacker can only access the system via the network, then the attacker may try to send any operation to any processes that provide network access. Further, if an attacker is in control of a process running on the system, then the attacker will try any means available to that process to compromise system security goals.
Image of page 24

Subscribe to view the full document.

New York Institute of Technology nyit.edu The Task of The Secure OS developer Protect the TCB from the threats mentioned in the previous slide. That way, can maintain security by limiting interactions of processes with data in the system. Protecting the TCB is more difficult because it interacts with many untrusted processes. Countermeasures for each threat are needed.
Image of page 25
New York Institute of Technology nyit.edu APPENDIX – WHAT IS A PROCESS?
Image of page 26

Subscribe to view the full document.

New York Institute of Technology nyit.edu Process A program is passive; a process active. Attributes held by a process include hardware state, memory, CPU, progress (executing) 3: Processes 27
Image of page 27
New York Institute of Technology nyit.edu WHY HAVE PROCESSES? Resource sharing ( logical (files) and physical(hardware) ). Computation speedup - taking advantage of multiprogramming – i.e. example of a customer/server database system. Modularity for protection.
Image of page 28

Subscribe to view the full document.