When you create a securable object, you can assign a security descriptor to the new object. The Win32 functions for creating securable objects, such as CreateFile or RegCreateKeyEx, have a SECURITY_ATTRIBUTES parameter that can contain a pointer to the new object's security descriptor. For sample code that builds a security descriptor and then calls RegCreateKeyEx to assign the security descriptor to a new registry key, see Creating a Security Descriptor for a New Object.
If an object's creator does not specify a security descriptor, the system uses inherited or default security information to create a security descriptor. The system component or server that manages the object can store the specified or default security descriptor to make it a persistent attribute of the object. You can use Win32 functions to change the information in an object's security descriptor.
Directory service objects, files, directories, registry keys, and desktops are securable objects that can have a parent object. When you create one of these objects, the system checks for inheritable ACEs in the security descriptor of the parent object. The system typically merges any inheritable ACEs into the ACLs of the new object's security descriptor. You can prevent a DACL or SACL from inheriting ACEs by setting the SE_DACL_PROTECTED or SE_SACL_PROTECTED bits in the security descriptor's control bits. For more information, see ACE inheritance.