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 stenographic 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 him. 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 stegoanalysis: 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 stegoanalysis: changes the initial stego target, therefore, it seeks to suppress the transfer of information, if it exists. See also References Sources External links An overview of digital steganography, particularly within images, for the computationally curious by Chris League, Long Island University, 2015 Examples showing images hidden in other images Information Hiding: Steganography & Digital Watermarking. Papers and information about steganography and steganalysis research from 1995 to the present. Includes Steganography Software Wiki list. Dr. Neil F. Johnson. Detecting Steganographic Content on the Internet. 2002 paper by Niels Provos and Peter Honeyman published in Proceedings of the Network and Distributed System Security Symposium (San Diego, CA, February 6–8, 2002). NDSS 2002. Internet Society, Washington, D.C. Covert Channels in the TCP/IP Suite1996 paper by Craig Rowland detailing the hiding of data in TCP/IP packets. Network Steganography Centre Tutorials. How-to articles on the subject of network steganography (Wireless LANs, VoIP – Steganophony, TCP/IP protocols and mechanisms, Steganographic Router, Inter-protocol steganography). By Krzysztof Szczypiorski and Wojciech Mazurczyk from Network Security Group. Invitation to BPCS-Steganography. Steganography by Michael T. Raggo, DefCon 12 (1 August 2004) File Format Extension Through Steganography by Blake W. Ford and Khosrow Kaikhah Computer steganography. Theory and practice with Mathcad (Rus) 2006 paper by Konakhovich G.