A desynchronized fingerprinting method and system for identifying
collaborators in the making of illegal copies of digital multimedia
products. The desynchronized fingerprinting system and method can be used
for both audio and video applications. The method and system include an
embedding feature and a detection and extraction feature. A different and
unique key is assigned to each buyer of a copy of the digital data. The
embedding feature includes applying a pseudo-random transformation to
selected embedding regions. The key for the pseudo-random transform is
user-specific. These regions are chosen by using a secure multimedia hash
function. The detection and extraction feature includes a brute-force
search in the key space of the buyers. If one of the keys is likely
enough, then it can be said that that user was been involved in the
production of an illegal copy.