How we broke the BOWS watermark

Abstract

From December 2005 to March of 2006, the Break Our Watermarking System (BOWS) contest challenged researchers to break an image watermark of unknown design. The attacked images had to possess a minimum quality level of 30 dB PSNR, and the winners would be those of highest average quality over three images. Our research team won this challenge, employing the strategy of reverse-engineering the watermark before any attempts to attack it in earnest. We determined the frequency transform, sub-band, and an exploitable quirk in the detector that made it sensitive to noise spikes. Of interest is our overall methodology of reverse-engineering through severe false alarms, and we introduce a new concept, "superrobustness," which despite its positive name is a security flaw.

Securing Digital Video

“…The Secure Digital Media Initiative challenge (SDMI) [299], the first Break Our Watermarking [301] highlighted the potential of this type of attack. In the event of an oracle attack, the attacker has access to an oracle that provides a Boolean answer if the challenge succeeds.…”

Tackling BOWS with the sensitivity attack

“…There was a prize to win in the first phase: a digital camera and 300 dollars. This prize was taken by Craver et al 1,2 from Binghamton University. After the first phase the algorithm used for embedding the watermark was revealed and the contest was open for a second phase that ended in the middle of June 2006.…”