1 ) Method to control the access to objects ( 5 ) stored in a memory space of a computer system by a subject ( 3 ) stored in a program space of said system wanting to perform an operation on said objects ( 5 ), characterised in that it controls the access to said objects ( 5 ) via a dynamic attribute ( 8 ) linked to said subject ( 3 ) whose value is updated according to the present and previous status(es) of the subject.