An apparatus includes a first processing unit to judge, whether the route information storing unit stores a second next destination address; a second processing unit to judge whether a received packet includes an message authentication code, in the case where the route-information storing unit stores the second next destination address; a third processing unit to judge whether the key-information storing unit stores a second shared key, which is a first shared key shared between the information processing apparatus, in the case where the received packet does not include the message authentication code for the second next destination address; a third packet generating unit to generate a third packet, which includes a next destination and information indicating that the generation of an message authentication code is impossible, in the case where the key information storing unit does not store the second shared key.