The phrase "a concealed message" is correct and usable in written English.
You can use it when referring to a message that is hidden or not immediately obvious, often in contexts like literature, communication, or espionage.
Example: "The author cleverly embedded a concealed message within the text that only the most observant readers would notice."
Alternatives: "a hidden message" or "an encrypted message".
The rendering is superb; you really feel that you've been holding that mahogany and gold box, that you found the hidden catch with your fingertips, that you yourself slid the secret panel up to reveal the concealed message.
For me it wasn't anything outstanding, but I know it will be one book on my shelf that makes me stop and stare for a while, because there's something intriguing about all these concealed messages.
Barely concealed messages lay embedded within the lines of these songs.
Second, he said, terrorists have trained their adherents "to pass concealed messages through unwitting intermediaries".
Shulsky's article involves Strauss's theory of esoteric writing, in which he notes that great philosophers, hesitant to tell the whole story of what they believed, used concealed messages in their writing.
Concealed messages can then be peeked at individually by holding your finger on the screen — a gesture every Snapchat user is familiar with.
In the case of Outlook.com, Microsoft reportedly worked with the NSA to help it get around its own data-scrambling scheme that would have concealed messages from the agency.
Before her marriage to Napoleon Bonaparte, Joséphine had her Pug Fortune carry concealed messages to her family while she was confined at Les Carmes prison, it having alone been given visiting rights.
A concealed old pot bust?
Its tongue was supposed to bear a drop of his blood, and the intricate pattern on the eggs was said to carry a concealed, possibly evil, message; these satanic associations sometimes led to the persecution of the bird.
