Canary
Noun · Security & Infosec
Definitions
A deliberately placed marker or value used to detect tampering, exploitation, or unexpected access, such as a stack canary, token canary, or canary document. If the canary changes or is touched, defenders know something suspicious happened.
In plain English: A marker placed to warn defenders if something has been tampered with or accessed unexpectedly.
Example: "The leaked file was actually a canary document, which helped identify the exfiltration path."