Steganography is the practice of hiding information inside ordinary-looking files. A message can be embedded inside an image, audio file, or document without altering its apparent appearance.
Unlike encryption, which makes content unreadable, steganography makes content invisible. The goal is not to protect the content of a message, but to conceal the fact that a message exists at all.
In adversarial contexts: steganography can be used to exfiltrate data inside seemingly innocuous files, or to communicate covertly through channels that are monitored. Detection tools exist but are not always reliable.
What it means in practice
Steganography is used in some intelligence and whistleblowing contexts to embed messages in images or audio files that appear ordinary. It is not a mainstream privacy tool — it requires both parties to have agreed on the method and key. Its primary relevance is awareness: files that appear to contain only an image may contain additional data, and some forensic tools scan for steganographic content in seized material.
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