
It's on the Batman flash drive
on your KEY chain.
The Big Bang Theory Season 11, Episode 9

So remember, the KEY is to be firm.
The Big Bang Theory Season 8, Episode 24

A decryption KEY needed
only in the unlikely event
Westworld Season 2, Episode 7

AUTOMATED VOICE:
Encryption KEY activated.
Westworld Season 3, Episode 8

I mean, Amy is the KEY
to your happiness.
The Big Bang Theory Season 7, Episode 21