@article {uvigo:survey-sec, title = {Watermarking security: a survey}, journal = {Transactions on Data Hiding and Multimedia Security I}, volume = {4300}, year = {2006}, month = {October}, pages = {41-72}, keywords = {data-hiding, security, watermarking}, author = {Luis P{\'e}rez-Freire and Pedro Comesa{\~n}a and Juan Ram{\'o}n Troncoso-Pastoriza and Fernando P{\'e}rez-Gonz{\'a}lez} }