Editing Steganography (section)

== Steganalysis ==
{{main|Steganalysis}}

=== Stegoanalytical algorithms ===
Stegoanalytical algorithms can be cataloged in different ways, highlighting: according to the available information and according to the purpose sought.

==== According to the information available ====
There is the possibility of cataloging these algorithms based on the information held by the stegoanalyst in terms of clear and encrypted messages. It is a technique similar to cryptography, however, they have several differences:

* Chosen stego attack: the stegoanalyst perceives the final target stego and the steganographic algorithm used.
* Known cover attack: the stegoanalyst comprises the initial conductive target and the final target stego.
* Known stego attack: the stegoanalyst knows the initial carrier target and the final target stego, in addition to the algorithm used.
* Stego only attack: the stegoanalyst perceives exclusively the stego target.
* Chosen message attack: the stegoanalyst, following a message selected by him, originates a stego target.
* Known message attack: the stegoanalyst owns the stego target and the hidden message, which is known to them.

==== According to the purpose sought ====
The principal purpose of steganography is to transfer information unnoticed, however, it is possible for an attacker to have two different pretensions:

* Passive steganalysis: does not alter the target stego, therefore, it examines the target stego in order to establish whether it carries hidden information and recovers the hidden message, the key used or both.
* Active steganalysis: changes the initial stego target, therefore, it seeks to suppress the transfer of information, if it exists.