Code Signing is the process of putting a signature on executables and patches to prove it is genuine, and to prevent attackers from injecting malicious code into end-user's systems.

Code signing comes up frequently in the following areas:

  • OS updates (especially Over-The-Air updates for mobile devices)
  • Firmware updates / secure boot
  • Installing apps from a public app store / downloaded from the internet

but can also come up in other contexts.