Non-translatable storage protection control system
Authorization mechanism for transfer of program control or data between different address spaces having different storage protect keys
Database encryption and decryption circuit and method using subkeys
File access security method and means
Protected software access control apparatus and method
Code protection using cryptography Patent #: 4757534
ApplicationNo. 066909 filed on 06/26/1987
US Classes:710/200, ACCESS LOCKING713/187COMPUTER PROGRAM MODIFICATION DETECTION BY CRYPTOGRAPHY
ExaminersPrimary: Williams, Archie E. Jr.
Assistant: Chan, Emily Y.
Attorney, Agent or Firm
International ClassesG06F 013/00
AbstractA method prevents an incorrect program version from being executed by a computer system. More specifically, a synchronization key is contained in a load module and is used to encrypt that load module which also contains a protected program. The encrypted load module with the protected program and synchronization key therein is stored in auxiliary storage. The synchronization key and program name are then placed in a table in a secure memory. When the program is requested for execution, the synchronization key in the protected table corresponding to the program name is used to decrypt the load module. The synchronization key in the load module is then extracted and compared with the synchronization key which is stored in a protected table and associated with the protected program. If the two synchronization keys are the same, then the decrypted protected program is loaded into the main memory for execution.