Source Article: https://developer.apple.com/news/?id=11302018a
Give users even more confidence in your software distributed outside the Mac App Store by submitting it to Apple to be notarized. When users on macOS Mojave first open a notarized app, installer package, or disk image, they’ll see a more streamlined Gatekeeper dialog and trust that it does not contain known malware. Starting spring of 2019, macOS Mojave will more prominently highlight notarization status. In an upcoming macOS release, Gatekeeper will require Developer ID–signed software to be notarized by Apple.