A Steganographic Algorithm for Hiding Data in PDF Files Based on Equivalent Transformation.

Xingtong Liu Quan Zhang Chaojing Tang Jingjing Zhao Jian Liu A Steganographic Algorithm for Hiding Data in PDF Files Based on Equivalent Transformation. 417-421 2008 ISIP http://doi.ieeecomputersociety.org/10.1109/ISIP.2008.35 conf/isip/2008 db/conf/isip/isip2008.html#LiuZTZL08