Gatekeeper and Developer ID

Gatekeeper is a new security feature of Mountain Lion that helps give users greater assurance when they download software from places other than the Mac App Store. As part of the Mac Developer Program, Apple gives you a unique Developer ID for signing your software. Learn how to use this ID for signing your apps and packages, and how Gatekeeper uses these signatures to verify that a downloaded app is not known malware and that it hasn't been tampered with.

WWDC 2012 - Session 702 - macOS