Information processing apparatus and unauthorized access prevention method

An unauthorized access prevention method executed by an information processing apparatus that includes a plurality of nodes having a first node and a second node each of which includes a processor and a memory in which at least a part of area is set as a shared memory area, and an interconnect that connects the nodes, the unauthorized access prevention method comprising:

• transmitting, using a processor included in the first node, identification information used for accessing a memory in the second node and attached to communication data to be transmitted to the second node;
• obtaining, using a processor included in the second node, identification information used for controlling permission to access, from another node, the shared memory area in a memory in the second node;
• and
• determining, using the processor included in the second node, whether or not an access to the shared memory area in the memory in the second node is permitted on the basis of the identification information that is attached to the communication data transmitted from the first node and the identification information obtained at the obtaining.