It is possible that you have recently received or are about to receive an email from Google informing you about a security update for Drive. There they tell you that as of September 13, 2021 the service will be updated to share files with greater security.
The problem with this is that the change can cause shared links break of your files, whether you use the free version, a Google One plan, or a Google Workspace plan. However, this is a welcome change as up to now link security has left something to be desired.
Blame it on the “semi-private” links
When we create a document or upload any file to Drive, we have two options to share: we can do it directly with a specific person or group of people with their email address, or we can get a link so that anyone who has it can open it.
That link is not private private but it is not public either public, as only whoever has the link in question can access the file. The problem with this is that those “semi-private” links are not that difficult to guess and therefore Google will be reinforcing them from now on.
Well, actually what it is reinforcing are the oldest links that date from before 2017. Google already knew that this was a problem and changed the way in which the links were generated in that year, however, all the generated links before January 1, 2017 they continue to use the above method which makes them easier to guess.
What will happen on September 13 is that all those old links will be forced to change and therefore, they will stop working for whoever has the previous link. On YouTube, which was almost the same with hidden videos, the change took effect on July 23.
GOOGLE DRIVE IS FULL! How to free up space on Gmail, Google Drive and Google Photos XTK Basics
How to know which of my files are affected and what to do
You can check directly at drive.google.com/drive/update-drives if you have files that require the security update. There you will see the complete list of your affected files and they will tell you if the security update has been applied to them (it will be done automatically on the date mentioned).
You have the option of remove the security update from any of your files in Drive to keep the old link working, although Google doesn’t recommend that you do so (obviously). Now if what you are concerned about is losing access to files that were shared to you in this way because the link will change, this at least will not be a problem … as long as you have accessed them before.
When this change was made on YouTube, all the hidden videos to which the link was changed were no longer accessible permanently, unless the owner of the account (if it was still active) took the time to delete the change. With Drive the process is different since Anyone who has accessed an old linked file with their account will still have access even after the security update.
Those left out are all those who want to access a file for the first time via a link without the security update. Sharing files in this way is more common than it sounds, and in too many cases real users expect the file to be either completely private or completely public and instead have something in between.
Block and unblock users in Google Drive
Together with these changes, Google Drive is also introducing other privacy and security measures in our accounts that will serve to eliminate annoyances: the option to block users in Drive.
When you don’t want someone to share files with you, you can block its owner, and therefore not even that person will be able to access any of your files and you will not be able to access theirs. You just have to right click on a file and select Block in the user’s email.