cipherkey

noun
UK /ˈsaɪfə kiː/
US /ˈsaɪfər kiː/

A secret key that helps you unlock or read a hidden message.

The detective used the cipherkey to read the spy's secret letter.


OTHER MEANINGS

2. A chart or table that shows how to swap letters to make or break a code.

The puzzle came with a cipherkey showing which letter stood for which.

3. A piece of information that lets a computer unlock protected data.

Without the cipherkey, the files on the laptop stayed locked.

4. A clue or hint that helps someone solve a mystery or puzzle.

The old map acted as a cipherkey to finding the buried treasure.