Watermarking approach to embedded signature-based authentication by channel statistics
Zhi-Fang Yang, Wen-Hsiang Tsai · Optical Engineering · 2003
Embedded signature-based authentication is a highly promis- ing watermarking method for solving high-level authentication problems. This work proposes such a watermarking approach using channel sta- tistics evaluated from a reference watermark. The basic concept is to consider the problem to be an example of communications with side information, which is the reference watermark embedded in the host with the signature at the sender site. At the receiver site, the reference wa- termark is first extracted to determine channel statistics, which are used to generate information about signature reliability. Three kinds of infor- mation are derived, including a reliability measure, an entropy measure, and an authenticated signature. Experimental results establish that the measures of reliability and uncertainty are meaningful, and that the em- bedded signature can survive high-quality JPEG compression and ma- nipulations such as negation, cropping, replacement, and modification. © 2003 Society of Photo-Optical Instrumentation Engineers.