The subject matter includes systems, engines, methods, and schemata for
embedding spread-spectrum fingerprints in multimedia content: a first
fingerprint to identify a recipient of the multimedia content and a
second fingerprint at a location in the first fingerprint that represents
a subset of a much larger group of recipients. By locating the second
fingerprint, the search for a media pirate is immediately narrowed down
to the subset, thus immensely speeding up pirate identification. In one
implementation, chips of the second fingerprint can be made small and
embedded sparsely, making alteration difficult. Systems, engines,
methods, and schemata for synchronizing a pirated copy with original
multimedia content to facilitate fingerprint recovery are also described.