Method and apparatus for protecting multiple copies of computer software from unauthorized use
Method and system for multimedia access control enablement
Method of software distribution protection
Method for generating a password using public key cryptography
Method and apparatus for copy protection for various recording media
Encrypted data package record for use in remote transaction metered data system
Methods for providing secure access to shared information
Secured electronic information delivery system having a three-tier structure Patent #: 5784460
ApplicationNo. 850729 filed on 05/02/1997
US Classes:705/54, Adding plural layers of rights or limitations by other than the original producer380/44, Having particular key generator380/45, Multiple key level705/57Copy protection or prevention
ExaminersPrimary: Hayes, Gail O.
Assistant: Sayadian, Hrayr A.
Attorney, Agent or Firm
International ClassH04L 009/00
AbstractA method and apparatus for securely transferring an encrypted-data key and a medium key, from a media storage such as a DVD disk to an output device in a computer system, using a randomly generated first secure transfer key generated by a disk drive of the computer system, the first key having a uniqueness factor derived from a phase locked loop circuitry. The first secure transfer key is combined with an output key stored in the output device forming a second secure transfer key. The second secure transfer key is used to encrypt the data key and the medium key to form a third secure transfer key. The third secure transfer key is passed to the output device where the data key and the medium key are decrypted. The data key and the medium key are then used by the output device to decrypt encrypted program data from the disk.