? List and explain the five steganalysis methods described by Neil F. Johnson and Sushil Jajodia.

Question

What will be an ideal response?

Answer 1

Neil F. Johnson and Sushil Jajodia described these steganalysis methods ("attacks"):?• Stego-only attack-Used when only the ?le containing the possible steganography content is available for analysis; it's similar to a cyphertext attack. This attack is one of the most dif?cult to perform because all you have to analyze is the suspected steganography ?le.?• Known cover attack-Used when the cover-media, the original ?le with no hidden message, and the stego-media, the converted cover-media ?le that stores the hidden message, are available for analysis. By analyzing the original and steganography ?les, further comparisons can be made to identify common patterns that might help decipher the message.?• Known message attack-Used when the hidden message is revealed later, allowing further analysis of new messages. Similar to the known cover attack, this method uses comparative analysis to decipher the message. Because the message is known, deciphering it takes less effort.?• Chosen stego attack-Used when a steganography tool and stego-media were used to hide the message content. Because this method uses a known steganography tool, the analyst applies password or passphrase recovery techniques to decipher the message. • Chosen message attack-Used to identify corresponding patterns used in stego-media. This technique creates stego-media and then analyzes them to determine how data is con?gured in the ?le. The analyst then uses these known con?guration patterns to compare with suspected stego-media to determine what the message might be.