English
magic cookie
From magic + cookie.
first attested First attested in c. 1979 (as stated in the etymology)
The story
First attested in c. 1979.
Today it means
noun A token or short packet of data passed between communicating programs, used to identify a particular event or transaction; the data is typically not meaningful to the recipient program and not usually interpreted until the recipient passes the data back to the sender or another program at a later time.
Language periods are conventional ranges, not dates for this word.
Etymograph / magic cookie