*Plausible deniability*: in some cases (for example, with <span class="application">VeraCrypt</span> hidden volumes), it is impossible for an adversary to technically prove the existence of an encrypted volume.
Still, [[!wikipedia Deniable_encryption desc="deniable encryption"]] might not protect you if you are forced to reveal the existence of the encrypted volume. See [VeraCrypt: Plausible Deniability](https://www.veracrypt.fr/en/Plausible%20Deniability.html).