Limitations On Number Or Amount Of Copies Patents (Class 726/31)
  • Data recording medium, data recording method and apparatus, data playback method and apparatus, and data determination method
    Patent number: 7039848
    Abstract: A recording medium includes an area in which data encoded with an error correction code is recorded. In the recording medium, data which contains an error uncorrectable with the error correction code, and data which does not contain an error uncorrectable with the error correction code are recorded in predetermined pattern.
    Type: Grant
    Filed: December 16, 2002
    Date of Patent: May 2, 2006
    Assignee: Sony Corporation
    Inventors: Tatsuya Inokuchi, Yoichiro Sako, Shunsuke Furukawa, Takashi Kihara
  • Method and apparatus for partial encryption of content
    Patent number: 6976166
    Abstract: The present invention is directed to methods and apparatus that partially encrypt an information data file. An exemplary method includes dividing the information file into a first file and a second file, wherein the second file includes content from the information file to preclude reconstruction of the information file using only the first file, and encrypting the second file. Additionally, the method provides for transmitting the first file and the encrypted second file from a first device to a second device.
    Type: Grant
    Filed: February 6, 2001
    Date of Patent: December 13, 2005
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Cormac Herley, Yihong Xu