Patents Assigned to Trustcopy Pte Ltd.
  • Optical watermark
    Patent number: 7366301
    Abstract: A multiple-layered watermark is generated to be placed on document, to protect against counterfeiting and forgery. Hidden information embedded into each of the watermark's layers is only detectable by using a corresponding decoder. Because of the multiple-layered structure, it is difficult to reverse engineer the optical watermark. The generalized watermark structure significantly increases the “key space” of the decoder.
    Type: Grant
    Filed: March 16, 2001
    Date of Patent: April 29, 2008
    Assignee: Trustcopy Pte Ltd.
    Inventors: Sheng Huang, Jian Kang Wu
  • Optical watermark
    Publication number: 20020054680
    Abstract: A multiple-layered watermark is generated to be placed on document, to protect against counterfeiting and forgery. Hidden information embedded into each of the watermark's layers is only detectable by using a corresponding decoder. Because of the multiple-layered structure, it is difficult to reverse engineer the optical watermark. The generalized watermark structure significantly increases the “key space” of the decoder.
    Type: Application
    Filed: March 16, 2001
    Publication date: May 9, 2002
    Applicant: Trustcopy Pte Ltd.
    Inventors: Sheng Huang, Jian Kang Wu