A communication apparatus which is connected to networks including first
network of first security level which is lowest security level and second
network of second security level, and is wirelessly connected to terminal
receiving terminal identifier and password which designates one of
networks, from terminal, selecting one of first security level and second
security level based on an authentication result of terminal, terminal
identifier, and password, forwarding, when second security level is
selected, data item which is transmitted from terminal and is encrypted
using cryptographic algorithm and cryptographic key to second network,
and forwarding, to terminal, data item which is transmitted from second
network and addressed to terminal, and forwarding, when first security
level is selected, data item transmitted from terminal to first network,
and forwarding, to terminal, data item which is transmitted from first
network and addressed to terminal.