The blog of content protection

The GIPSA lab of INPG Grenoble organizes BOSS (Break Our Stegano System) challenge. Attackers will have access to a database of 1,000 pictures. Half of them are steganoed using a system called HUGO. The payload will be the same for every steganoed picture. Attackers have the source code of HUGO. The objective is to discriminate through steganalysis the stega pictures from the cover pictures.

The challenge is interesting. Regularly, the newspapers disclose story of unlawful people using steganography to hide message on the web. In these stories, the attackers/governmental agencies have not the advantages of knowing the used algorithms.

BOSS should remind you BOWS2. The GIPSA lab organized the same type of challenge but for watermark.

Do you want to add a digital watermark to your personal pictures or audio records? The MyDRMspace site offers such a free service free (although in the terms of use, there is a possibility to charge).

Polish developers and entrepreneurs opened this site in 2009. Once registered, you can upload a photo or a piece of audio to the server. Then, you enter information related to the file and mydrmspace will add a watermark to it (signature in their vocabulary). Of course, you can upload a file to check if any watermark is present. If the watermark is present, then mydrmspace will point to the corresponding information.

The developers had the bright idea to offer the infrastructure as a platform for watermark designers. Any watermark designer can upload his/her embedders and detectors (so called coder and decoder on the site ) Then the public may use this technology. In other words, when uploading to mark, you can choose the embedder (coder). I have no clue on which criteria, normal users would use one technology rather than another one. The most probable would be that normal user would choose either the first one presented or the most popular one. When checking a file, you have to select the right detector (decoder).

Unfortunately, they seem not to have tremendeous success. There is only one audio watermark technology available and two image watermark technologies (from the same author). The place holder for video watermark is empty.

I have not tested if the watermarks are robust.

Do you know any similar site that offers free watermarking service?

Thank you to TF for the pointer

Screeners are copies of a movie that are sent to reviewers or members of an award jury. The favored format is DVD. Unfortunately, DVD are not protected against piracy. Thus, typical procedure is to watermark each screener with an individual invisible mark. Thus, if ever there is leakage, it should be possible to trace back to the originator.

According to /Film, Sony pictures considered this operation too expensive and thus decided not to support its movie “Moon” for the Oscars. Funnily, the movie is already available as DVD and BluRay.

Is the story finished?

Thanks to Olivier for the pointer.

Amazon has filed an interesting patent titled System and method for marking content. The idea is rather simple. Create a dictionary of synonyms. To uniquely mark a piece of textual content, permute a set of defined words by selected synonyms. Of course, the patent explores all the alternatives, but in a nutshell this is the main idea.

For the fun, here is the first claim

1. A system, comprising: a processor; and a memory comprising program instructions, wherein the program instructions are executable by the processor to: receive a request for particular content; extract a copy of the requested particular content from a content collection, wherein the particular content includes textual data; substitute a synonym for each of one or more selected words in the textual data of the copy, wherein to substitute a synonym for each of one or more selected words, the program instructions are further executable by the processor to: access a synonym database comprising a plurality of key words, wherein each key word is associated with one or more synonyms in the synonym database; and select a particular synonym to substitute for a particular selected word in the textual data of the copy from one or more synonyms associated with a key word in the database that matches the particular selected word in the textual data of the copy; and return the copy with the substituted synonyms in response to the request.

Does it work? For watermark, there are typically three parameters to examine:

• • Transparency: There are some issues. First of all, it probably is not applicable to literature. Synonyms are rarely perfect and authors may not accept modifications of their text. Nevertheless, for many texts, and for non-purists, it may be rather transparent. Although I’m not sure that there may not be some readable artifacts.
• • Robustness: It is obvious that it is easy to detect some substitutions. If the content is not protected in integrity, it is rather easy to wash or forge a new marked content. If the purpose is to fight piracy (such as illegal redistribution), it will not work. The hacker will remove the integrity protection and substitute.
• • Payload: This depends of the text’s length and the variety of the used vocabulary.

It is an interesting approach although not robust. In some specific contexts, it may have some interest.

Thanks to JJQ for pointing to this patent.

The movement towards DRM free music continues. The biggest event is of course iTunes that announces that its complete catalog will be available as DRM free songs. iTunes announced also a new price list adding $0.69 songs (in addition to $0.99 and $1.29)

Warner France followed this movement. It announced that its two sites Fnac Music and Virgin Media will sell DRM free songs in 2009. Nevertheless, it is a trial and the final decision will be taken in 2010.

DRM free music is a trend that will not stop. Will it extend to other fields such as games or video? I am not sure. of course, customers would like it. DRM free distribution with a session watermark to detect eventual illegal distribution is promoted, for instance by the Digital Watermark Alliance.. Nevertheless, there are several differences with music. According to me, the biggest one is that the investments are far huger than music. In the case of video, the release windows strategy and commercial agreements are also problems.

We will continue to monitor this trend in 2009.