Patents by Inventor Zong Wei Liu

Zong Wei Liu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7296159
    Abstract: Methods and apparatus for key distribution in a conditional access system, assuming that the set of all user nodes which the system can accommodate is a complete set, and a subset is composed of all user nodes or part of user nodes. One method comprises: decomposing said subset into at least one secondary subset; assigning a different user key to each secondary subset, each said user key being transmitted to all users in a corresponding secondary subset; encrypting an entitlement key by using each said user key so as to generate a cipher text corresponding to each said secondary subset; and combining said cipher text to generate a media key control block and transmitting said media key control block to all users in said subset. Since a classification method of a binary tree and a multiple tree is used, the invention can save a lot of network resources.
    Type: Grant
    Filed: September 22, 2003
    Date of Patent: November 13, 2007
    Assignee: International Business Machines Corporation
    Inventors: Jian Zhang, Zong Wei Liu, Ling Shao, Dong Xie
  • Publication number: 20040120529
    Abstract: Methods and apparatus for key distribution in a conditional access system, assuming that the set of all user nodes which the system can accommodate is a complete set, and a subset is composed of all user nodes or part of user nodes. One method comprises: decomposing said subset into at least one secondary subset; assigning a different user key to each secondary subset, each said user key being transmitted to all users in a corresponding secondary subset; encrypting an entitlement key by using each said user key so as to generate a cipher text corresponding to each said secondary subset; and combining said cipher text to generate a media key control block and transmitting said media key control block to all users in said subset. Since a classification method of a binary tree and a multiple tree is used, the invention can save a lot of network resources.
    Type: Application
    Filed: September 22, 2003
    Publication date: June 24, 2004
    Applicant: International Business Machines Corporation
    Inventors: Jian Zhang, Zong Wei Liu, Ling Shao, Dong Xie