Introduction to Information Security

Access rights

• Access rights control whether or not a particular user can use or edit a program or data file.
• Each user is assigned different rights which determine the files that can be accessed. A user may be allowed complete access to a file or may be restricted only to read the data or have no access at all.
• Network operating systems provides a way of identifying individuals (for example by a user ID and password). Each individual can only access resources the user is given privileges for by the network manager.
• Some files have additional access restrictions provided by password protection. When a user attempts to gain access to one of these files an additional password will be requested before access is allowed. This provides extra security

Computer Systems Security

Operation systems security hardening

Operating System Security Terms and Concepts

• An operating system manages and controls access to hardware components
• Older operating systems focused on ensuring data confidentiality
• Modern operating systems support four basic functions
• Positively identify a user
• Restrict access to authorized resources
• Record user activity
• Ensure proper communications with other computers and devices (sending and receiving data)

Organizing System Security

• First steps in security are identifying and authenticating a user
• Typically through username/password combination
• Third step is to authorize a user for specific access
• Can be based on roles, security labels, identification, etc.
• Security functionality is generally layered
• At least a user layer and a kernel layer
• The reference monitor that intercepts and authorizes requests is part of the security kernel
• Kernel programs often have a high privilege level