In the comments section, an anonymous person said: “The only thing that I really didn’t like is the same for all of the Mint systems and that is the poor security you get by using their unsigned packages and repositories.”

–> It is the same for all Mint systems indeed. It’s a feature though and it’s even a condition for our ISOs to pass the QA tests. Both the main Mint repositories and LMDE are signed and secure. The warning you see is because we set APT to allow unauthenticated repositories. This follows our philosophy that if you told your system to do something, it should listen to you and do it promptly. If for any reason you decided to add an unsigned repository, then Mint should accept it and do as it’s told. You already have a warning, if you don’t like it, use sign repositories, if you do already, remove the setting from /etc/apt/apt.conf. This default setting is there to warn people and to let them do what they want, as opposed to something that fails when you need it most. You’re not more exposed than on any other system. If something has the rights to modify your /etc/apt/sources.list it surely has the rights to modify /etc/apt/apt.conf as well. Warnings are good things and unlike errors they’re here to let you know about things without getting in your way. This is not poor security. This is a signed and secure system which lets you add additional sources, signed or not, the day you feel like it.

The warning you see is because we set APT to allow unauthenticated repositories. This follows our philosophy that if you told your system to do something, it should listen to you and do it promptly. If for any reason you decided to add an unsigned repository, then Mint should accept it and do as it’s told. You already have a warning, if you don’t like it, use sign repositories, if you do already, remove the setting from /etc/apt/apt.conf. This default setting is there to warn people and to let them do what they want, as opposed to something that fails when you need it most. You’re not more exposed than on any other system. If something has the rights to modify your /etc/apt/sources.list it surely has the rights to modify /etc/apt/apt.conf as well. Warnings are good things and unlike errors they’re here to let you know about things without getting in your way. This is not poor security. This is a signed and secure system which lets you add additional sources, signed or not, the day you feel like it.