1) Cryptographic attack 
Steganalysis is the study of detecting messages hidden using steganography; this is analogous to cryptanalysis applied to cryptography. == Overview == The goal of steganalysis is to identify suspected packages, determine whether or not they have a payload encoded into them, and, if possible, recover that payload. Unlike cryptanalysis, where it is ...
steganalysis Analyzing and deciphering steganographic or secret writing.