Update README

README.md

@@ -194,6 +194,7 @@ A detailed description of these options with examples can be found [here](https:
 - ⚠️ Padding is not used to create a MAC tag (only ciphertext and salt will be authenticated).
 - ⚠️ `tird` does not sort digests of keyfiles and passphrases in constant-time.
 - ⚠️ Overwriting file contents does not guarantee secure destruction of the data on the media.
+- ⚠️ You cannot prove to an adversary that your random-looking data does not contain encrypted data.
 - ⚠️ Development is not complete; there may be backward compatibility issues in the future.
 
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