A data processing apparatus is provided which is capable of improving the responsiveness of communication in which only a maximum of one access request source has write authorization and the other access requests do not have write authorization when communication is performed with a plurality of access request sources. A management apparatus transmits, to a secure application module (SAM), a strong connection request requesting the obtainment of write authorization into the SAM. When it is determined that the strong connection has not already been assigned to the other management apparatuses, the SAM assigns the strong connection to the management apparatus in a state in which a weak connection having read authorization with the management apparatuses is maintained.