JDK 14 is the first release that complies with the new macOS 10.15 hardening and notarization requirements. See Notarizing Your App Before Distribution. When you install or run software for the first time, Gatekeeper verifies that the software has been notarized. With macOS 10.15, Apple introduced new application security checks, which are used by Gatekeeper to verify the contents of distributed software.
