Steganography vs Cryptography

Cryptography and steganography are complementary disciplines with different goals. Cryptography transforms a message so that its content is unintelligible without the key, but the existence of a secret message is obvious. Steganography hides the very existence of the communication inside an innocent-looking carrier medium, so an observer does not know a secret message is present at all.

The most secure covert communication combines both techniques: first encrypt the message so that even if the hidden data is detected, it cannot be read; then embed the ciphertext inside a carrier using steganography. An attacker who finds the hidden data sees only random-looking bytes. This layered approach is used in both legitimate privacy tools and in nation-state intelligence operations.