Relay apparatus

A relay apparatus for relaying data in a network comprises: a storage configured to store therein a whitelist in which normal information is registered, the normal information indicating that said data is normal based on a destination and source thereof; a receiver configured to receive first data; a determining part configured to determine whether normal information for the first data received is registered in the whitelist or not; a rewriting part configured to rewrite, when the determining part determines that the whitelist does not have normal information of the first data, a remaining lifespan required to reach the destination of the first data to a prescribed lifespan required to reach a specific communication apparatus that exists between the nearest communication apparatus and the furthest communication apparatus from the relay apparatus in the network; and a transmitter configured to transmit the first data that has gone through a rewriting process.