Yanmin Zhao and  Siu Ming Yiu,  A Watermarking Signature Scheme with Hidden Watermarks and Constraint Functions in the Symmetric Key Setting.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    June 2020, vol. 163(7). 270 - 277
    [viewed 04 May 2024]. Available from: https://publications.waset.org/pdf/10011335.