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TechKnowSurge Catalog Videos OS Functions: Access Control
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OS Functions: Access Control

Operating system access control determines who can view, modify, or execute files and other resources on a computer. Permissions can be assigned or denied at the user and group level to protect sensitive data from unauthorized access.

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About this video

Access control is one of the fundamental responsibilities of an operating system, ensuring that only authorized individuals can interact with the data and resources stored on a machine. Without it, any user, whether local or remote, could potentially read, copy, or alter files without restriction, creating serious security risks for individuals and organizations alike. Files and folders serve as a straightforward example of how access control works in practice, though the same principles apply to virtually every object on a system. Each file or folder carries an associated set of permissions that govern what specific users and groups can do with it. On Windows systems, these permissions are managed through the Security tab in a resource's properties, where administrators can see which users and groups have access and what level of access each one holds. Permissions can be configured to allow or explicitly deny specific actions, such as reading, executing, or modifying a resource. Administrators can add new users to a permission list, adjust existing entries, or lock down a resource entirely so that only a designated account retains access. Understanding how to read and configure these permission settings is an essential skill for anyone responsible for securing systems or managing user environments.

What you'll learn

What's covered

OS Access Control

Aligned to

CompTIA Tech+
6.4 Compare and contrast authentication, authorization, accounting, and non-repudiation concepts.
CompTIA A+ Core 2
2.5 Given a scenario, manage and configure basic security settings in the Microsoft Windows OS.
3.2 Given a scenario, troubleshoot common personal computer (PC) security issues.
CompTIA Server+
3.3 Given a scenario, implement group policies and access controls.

Key terms

Access Control
A security mechanism that restricts access to resources based on policies, roles, or identity.
Authorization
The process of determining what actions or resources an authenticated user is permitted to access.
Least Privilege
A security principle that grants users and systems only the minimum access rights needed to perform their functions.
File and Folder Permissions
Settings applied to files and folders that define which users or groups can read, write, execute, or modify those resources.
Role-Based Access Control
RBAC
An access control model that assigns permissions based on a user's role within an organization.

Topics

Access Control Operating Systems File Permissions User Permissions Group Permissions Os Security

Transcript

Another important role that your operating system does is access control. You wouldn't want just anybody to be able to get onto your computer and have access to all of the files on it. Neither would you want somebody to remotely get onto your computer without you ever knowing and be able to start copying files off of your computer. So your operating system has an element of access control to help.

Files and folders as an example

One easy way to show access control is through the files and folders. It's a big part of access control, but it's not the only thing. There are different objects on your computer, and all of these different objects have a certain level of security or access control on them. But let's just use a file or folder as an example. If I've got a folder or file and I only want myself to have access to it, I can lock it down so no one else does.

Looking at folder permissions

Let's take a look at some folder permissions and see what it looks like. Here's the configs folder right here, and I'm going to right click on this configs folder and go to properties, and I can click on this security tab to see what's inside the security tab.

I've got groups and user names here. The system, the demo laptop and administrator are the groups and users in here. The groups are the ones that have two people next to them, and the user is the one that just has a single person. When you click on here, what happens is down here it shows you what the permissions are. Now all of these have the same level of permissions, so there's nothing different here.

But if I wanted to change something, I can click edit here and I can go through and change, or let's say deny, and start denying one of these permissions into the system. So maybe I want to deny the read and execute for administrators, for systems. Maybe I just want to do the modify and demo laptop. So you can see I can change there: all the allows are grayed out. I could add a user to this and be able to make some other changes to it, but I'm not going to do that right now. Just know that this is where I can go in and grant access or deny access to this resource.

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