integrated information and telecommunication systems operate subsystems with their own systems of access differentiation. At the stage of subsystems modernization there is a possibility to change the parameters or structure of their access differentiation systems. This fact is a prerequisite for violation of the information properties, contained in the general field of the integrated information and telecommunications system. Analysis of the existing ways of the unauthorized information flow appearance during usage of discretionary models in the access differentiation systems has shown a possibility of information properties violation. A method for harmonization of access matrices of various options of the discretionary differentiation of access systems has been developed. The security theorem of joint functioning of different options of access differentiation systems, built on the bases of a discretionary model, is formulated and proved.