The lock screen of operating systems is the one in charge of separating our personal data from people who do not have permission to use the PC. This is the screen that usually appears as soon as you turn on the PC, and when the computer is not used for a long time. It is the one that, to unlock the PC, will ask us for our password or the authentication method that we configure. Broadly speaking, it is the most basic security layer of any PC. But, if only we use it, more than security, the only thing it gives us is a waste of time.
Ubuntu, like any other operating system, has a corresponding lock screen. And this appears in two moments: when starting up and when we are not using the PC for a while. From it we can select the user we want to use, enter the password and that's it.
However, if we do not want to use this lock screen to improve the workflow of our Linux, then we will see how we can deactivate it in two different ways.
Disable user lock screen when turning on PC
When we turn on Linux, after loading systemd, we will see the home screen. In it, all the users that we have created will appear, and we can choose with which of them we want to start using Ubuntu.
This screen will always appear, regardless of the number of users that we have created, as long as the automatic login is not activated. To do this, what we must do is open the Configuration menu of our distro, and go to the "Users" section. The first thing we will do is unlock the options by clicking on the button that appears at the top of the window to be able to modify them.
Once this option is deactivated, we can modify these settings. We are interested in automatic login, therefore we will check this box and save the changes.
From now on, when we turn on the PC, the session will automatically start for our user without seeing this lock screen after boot.
Prevent Ubuntu from crashing after idle time
One of the essential security measures for any computer system is to lock it when we are not sitting in front of it. This way we can be sure that nobody touches our PC without permission or gossips among our data. Normally, operating systems are usually configured so that, after a certain time of inactivity (a few minutes, hours, etc.) it is automatically blocked. the session is still open, but to be able to use the PC we will need to enter the password again in it.
Ubuntu, as expected, allows us to modify these parameters. The screen lock configuration options can be found in the "Privacy" section, within the Settings menu.
From here we will be able to configure everything related to blocking the computer. For example, we can choose how long we want it to pass until Ubuntu turns off the screen (without locking), if we do not want the automatic lock to be activated, combine the two options (turn off the screen and then lock) and also if we want the session to be lock automatically when the computer is suspended or if we want to see personal notifications on this lock screen.
We can configure these parameters to our liking. If we live alone, we can leave the lock screen deactivated, but if we live with other people and we are concerned about our privacy, then it is necessary to have it activated, since it will help us to prevent other people from taking advantage of when we are not around to access our computer.
Two users? You must use the lock screen
The above is effective, and safe, when we only have one user on the PC: ours. However, if we already have another user created, it means that we are sharing a PC with another person. Therefore, the lock screen is important so that each user's data is safe , and also to be able to choose which user to open when the PC is turned on.
Can we disable it? Of course, nothing prevents us. But we must bear in mind that, every time we turn on the PC, it will automatically start the session with the user who has configured it, so if it is the other person who has access to the PC, they will be able to access all our data. And, to reach your username, you have to manually log out to open the new one.
If we worry about locking the PC every time we get up from the chair (from the GNOME menu, with a keyboard shortcut, etc.), then what we can disable is the automatic system lock.
Other security measures to protect Linux
The lock screen is a very basic layer of protection. It can help us prevent other people from accessing our session and data from the system itself. However, they can always load another operating system, and even remove the hard drive from the PC, to connect it to another computer and access all its information as if it were just another external hard drive.
To prevent this from happening, what we must do is resort to other settings such as disk encryption . Either with the Linux utility itself, or with third-party tools such as TrueCrypt, if we encrypt the data on the disk, nobody or nothing will be able to read it. When we turn on the PC, a screen will appear directly, before loading the operating system, which will ask us for the password.
Once we enter the password, the data will be decrypted and the system will begin to load. If we do not enter the password, no one will be able to recover the data, not even if they mount the hard drive on another computer with another operating system. Of course, to be safe we must make sure to enter a password as secure as possible, or we will have problems.