Semantic Steganography

A hybrid scheme: the service header is hidden in zero-width characters, while the main encrypted message is encoded by choosing word replacements in ordinary text.

Hybrid mode: there are far fewer invisible characters here than in ordinary text-stego, because the main payload is transferred into the visible text via word pairs.
Important: this is a practical v1 mode with a limited replacement dictionary. It masks the very existence of data better than a pure ZW channel, but has lower capacity and is sensitive to manual editing of the resulting text.
Each bit needs one suitable token from the replacement dictionary. If the text is not enough, the tool will show an error.
Argon2id AES-CTR + HMAC-SHA256 ZW header only Semantic payload
The algorithm encrypts the message, serializes the bundle, and turns it into bits. After that, a short service header stores the signature and payload length, while the bits themselves are distributed across the text through the choice of words from predefined pairs.
Example logic: one word of the pair means 0, the other means 1. Thus the resulting text stays readable, and the hidden channel is moved from the level of invisible characters to the level of lexical variants.
Limitations: a small dictionary, dependence on the language of the text, and sensitivity to subsequent editing. If carrier words are changed after embedding, the message may stop decrypting.