The aim of this work is to analyze suitability of existing internet multimedia storage services to use as a covert (steganographic) transmission channel. After general overview we focus specifically on the YouTube service. In particular, we study the feasibility of the recently proposed new steganographic technique \cite{wseas} of hiding information directly in the structure of the mp4-encoded video file. Our statistical analysis of the set of 1000 video files stored by this service show the practical limitations for this type of information hiding.
steganography, mp4 file, multimedia storage, YouTube
93E12, 62A10