While this might be a move to increase the security and reduce malicious software infections on end-users computers, all applications are required to be digitally signed with an Apple Developer ID and thus each installer must be recompiled by the developers. Another change is that Gatekeeper will run its list of checks every time you open an app.Since version 10.8, Mac OS X features the so-called 'Gatekeeper' security mechanism, which prevents installations from dubious developers. Previously you could get around Gatekeeper by launching the app via Terminal but now if you open an app via Terminal Gatekeeper will still check it out.

In macOS Catalina, which was introduced in October 2019, Apple made Gatekeeper even more stringent. Then, even if it matches those requirements, Gatekeeper will ask you to confirm that you want to open the app. It also checks whether the app is written by a developer known to Apple (aka Signed). These measures include Gatekeeper, which is Apple’s name for the security aspect of macOS that checks apps for malware and quarantines them. While we can all follow the advice not to download apps from file-sharing sites, or via links on dodgy looking emails, Apple’s basically put in measures to make it harder for us to install apps that might be dangerous. It might even look like a well-known app, but have malicious code added to it.

These measures are designed to protect us from malware that might arrive on our Macs disguised as an app that we think we can trust. As we said above there is good reason for this.

Mac gatekeeper settings