×

Watermarking process resilient to collusion attacks

  • US 5,664,018 A
  • Filed: 03/12/1996
  • Issued: 09/02/1997
  • Est. Priority Date: 03/12/1996
  • Status: Expired due to Term
First Claim
Patent Images

1. A watermarking method, comprising the steps of:

  • (a) generating a digital string from the work to form a baseline watermark;

    (b) generating a set of watermarks each having a predetermined relationship to the baseline watermark; and

    (c) inserting a respective one of the set of watermarks into a respective copy of the work to create a watermarked copy uniquely identified by the respective one of the set of watermarks; and

    (d) repeating step (c) at least m times to create a set of m watermarked copied, each having a different one of the set of watermarks therein, such that if a subset of said m watermarked copies are averaged to produce an illicit copy of the work, at least one of the set of watermarks is detectable in the illicit copy.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×