Desynchronized image fingerprint for large scale distribution

Collusion is a major menace to image fingerprint. Recently, an idea is introduced for collusion-resilient fingerprint by space desynchronizing including RST (rotation, scaling and translation) and random bending. In this paper, we proposed a new space desynchronized fingerprint method which is for large scale distribution: image is enlarged and encrypted at sender side; at user side, key sequence is used to only decrypt some parts of image and compose these parts to make a new image copy with fingerprint embedded. This method has two priorities: first, only one image is needed to send to or be downloaded by all users with fingerprint embedded; secondly, the embedded fingerprint is robust to collusion attack. For diminishing the degradation introduced by desynchronization, we consider the image content such as human face. Experiments indicate the effectiveness of our method.