Systems for fingerprinting digital data are described. In one embodiment,
a system for detecting a fingerprinting word is configured to receive a
protected object that has embedded therein a fingerprinting word that
contains a plurality of spread spectrum chips that are arranged in
individual blocks that define individual spread sequences. The system
processes the protected object sufficient to identify an entity that is
associated with the fingerprinting word and which comprises a potential
colluder. The system is configured to process the protected object by
calculating a weight for each block and restricting the weights of
certain blocks to a predetermined value.