Which concept involves concealing the existence of a message rather than its content?

• A. Concealment of content of a message
• B. Concealment of existence of a message
• C. Encryption of a message
• D. Hiding a message in transit

Answer: (B)

Concealing the existence of a message is about hiding that any secret communication is taking place at all. This is the essence of steganography or covert channels: the payload may be present, but observers cannot detect that a secret message exists or is being transmitted. Encryption, on the other hand, focuses on protecting the content so that anyone who sees the message cannot read it, but the fact that a message is being sent can still be observable. Hiding a message in transit refers to embedding data within a carrier or channel to avoid raising suspicion, which is related but doesn’t explicitly target the broader goal of making the very existence of the message undetectable. Therefore, concealing existence best matches the concept described.