Method for protecting data in a computer system

• US 5,414,852 A
• Filed: 10/30/1992
• Issued: 05/09/1995
• Est. Priority Date: 10/30/1992
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Tate, Kay A., Kramer, Paul H.
• Primary Examiner(s): Kriess, Kevin A.
• Assistant Examiner(s): BACKENSTOSE, JONATHAN
• Application Number:
  US07/969,678
• Time in Patent Office: 921 Days
• Field of Search: 364/969.4, 364/969, 364/969.2, 364/969.3, 364/246.6, 364/246.8, 364/246.9, 395/700, 395/246.6, 395/246.8, 395/246.9, 395/969, 395/969.2, 395/969.3, 395/969.4
• US Class Current: 718/104
• CPC Class Codes: G06F 21/6218 to a system of files or objects, e.g. local or distributed file system or database
• CPC Class Codes: G06F 2221/2141 Access rights, e.g. capability lists, access control lists, access tables, access matrices

Abstract

A data processing system include a plurality of data objects which are accessible by application programs through a system level interface. Each data object has an associated user access list. In addition, each object has at least one key indicating which applications can access that object. The key is preferably maintained in a protected storage area, accessible only by the low level system interface. Both the application identifier key and the user who invoked that application must match the identifier information in the data object for access to be allowed to that object. If an unauthorized user attempts access to the data object through the correct application, or an authorized user attempts access through an incorrect application, access to the data object will be denied by the low level interface.

Claims

1. In a data processing system, a computer-implemented method for controlling access to a plurality of data objects, comprising the steps of:

when each of the plurality of objects is created, associating with such object at least one user identifier, and at least one list of data manager identifiers;

invoking a first data manager using a user identifier to identify an invoking user;

invoking a second data manager from the first data manager; and

when the second data manager later attempts to access a data object, allowing such access only if one of the lists of data manager identifiers associated with the data object contains both the first and second data managers, and the first data manager has been invoked with a user identifier associated with the object.

2. The method of claim 1, wherein each data object is created by a data manager, and an identifier of the creating data manager is included in one of the lists of data managers associated with each created object.

3. The method of claim 2, wherein identifiers for at least three data managers are included in one of the lists associated with at least one selected data object.

4. The method of claim 2, wherein a list of user identifiers associated with a data object can be modified by the data manager which created the data object.

5. The method of claim 2, wherein data objects are created by data managers through a system level interface, and the data manager identifier associated with each data object is accessible only by the system level interface.

6. The method of claim 1, wherein each user identifier associated with each data object has a type of access permission, and access to that data object by a process utilizing any particular user identifier is allowed to perform only those actions defined by the access permission type.

7. The method of claim 6, wherein the access permission types include read for read only access, write for write access, and delete for delete access.

8. The method of claim 1, wherein each data manager associated with any particular data object has a type of access permission, and access to that data object by a process utilizing any particular data manager identifier is allowed to perform only those actions defined by the access permission type.

9. The method of claim 8, wherein the access permission types include read for read only access, write for write access, delete for delete access, and update for access to the associated user identifiers for modification thereof.

10. A computer-implemented method for controlling access to a plurality of data objects in a data processing system, comprising the steps of:

for each data object, providing a user list containing at least one user identifier, and a data manager list containing at least two data manager identifiers;

each time a data manager accesses a data object, comparing an identifier for such data manager with the data manager list for such object, and comparing a user identifier of a user which invoked the data manager with the user list for such object; and

permitting access to the data object only if the user identifier is contained in the user identifier list, each of the data manager identifiers are contained in the data manager identifier list, and each of the data managers in the data manager list has been invoked in a chain to access the selected data object.

11. The method of claim 10, wherein each user identifier contained in the user identifier list of each data object has a type of access permission, and access to that data object by a data manager utilizing any particular user identifier is allowed to perform only those actions defined by the access permission type.

12. The method of claim 11, wherein the access permission types include read for read only access, write for write access, and delete for delete access.

13. The method of claim 10, wherein each data manager contained in the data manager identifier list of each data object has a type of access permission, and access to that data object by a data manager utilizing any particular data manager identifier is allowed to perform only those actions defined by the access permission type.

14. The method of claim 13, wherein,the access permission types include read for read only access, write for write access, delete for delete access, and update for access to the associated user identifiers for modification thereof.