Patents by Inventor William James Richards

William James Richards 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).

  • Multiple keys for decrypting data in restricted-access television system
    Patent number: 6690795
    Abstract: An encryption system for restricted-access television systems. Multiple decryption keys are used to decrypt encrypted material which is transmitted to customers of a restricted-access television system.
    Type: Grant
    Filed: March 4, 1997
    Date of Patent: February 10, 2004
    Assignee: Lucent Technologies Inc.
    Inventor: William James Richards
  • Method and apparatus for providing hierarchical key system in restricted-access television system
    Patent number: 6069957
    Abstract: An encryption system for restricted-access television systems. Decryption keys, which are used to decrypt program material, are transmitted to customers in a restricted-access television system. The keys are transmitted as a hierarchy, wherein one key unlocks another key, and the last key unlocked is used to decrypt program material. Such a hierarchy is sometimes called "key-upon-key" encryption. The system transmits a second key that produces a first key from a cipher text (which first key decrypts a first program material) and wherein the second key also decrypts a second program material.
    Type: Grant
    Filed: March 7, 1997
    Date of Patent: May 30, 2000
    Assignee: Lucent Technologies Inc.
    Inventor: William James Richards