SECURITY MECHANISM FOR A COMPUTER SYSTEM

A computer system includes a plurality of programs and a plurality of accessible objects. Each program has an associated program identifier, and at least some of the objects have respective access control lists (ACL). Each ACL entry may comprise a program identifier key and an access permission indication. When a user attempts to access an object by way of a program, an entry in the ACL of the object is selected by matching the entry keys with at least the program identifier of the program, and access is granted or denied on the basis of the access permission indication in the selected entry.