I'm studying the basics of security in computers. The doubt I have is that the access control matrix is presented as a matrix whose rows are the subjects and the columns are the objects. Also subjects are defined both in Windows and Unix (and Multics for that matter) as processes, threads, not users, but processes.
My question is why then, when I check the Windows ACLs, I get the permissions that each user has instead of the permissions that each process under each user has.
It seems to me that more than a matrix a cube is needed, because the subject permissions, i.e. the processes permissions, are bound to the identity of the user logged in.
From what I've read it seems ambiguous: in some cases subjects are processes, and in others subjects are user accounts. Which one is the correct form?