Method and apparatus for enabling trial period use of software products: method and apparatus for passing encrypted files between data processing systems Patent #: 5563946
ApplicationNo. 712630 filed on 09/04/1996
US Classes:713/165, File protection705/51Usage protection of distributed data files
ExaminersPrimary: Gregory, Bernarr E.
Attorney, Agent or Firm
International ClassesH04L 009/32
AbstractA method and apparatus is provided in a data processing system for securing access to particular files which are stored in a computer-accessible memory media. A file management program is provided as an operating system component of the data processing system. A plurality of files are stored in a computer-accessible memory media, including at least one encrypted file and at least one unencrypted file. For each encrypted file, a preselected portion of the file is recorded in memory, a decryption block is generated which includes information which can be utilized to decrypt the file, and the decryption block is incorporated in the file in lieu of the preselected portion which has been recorded in memory. Then, a file management program is utilized to monitor data processing system calls for files stored in the computer-accessible memory media. The file management program determines whether the called file has an associated decryption block. The called file is processed in a particular manner dependent upon whether or not the called file has an associated decryption block.
Field of SearchMISCELLANEOUS