| 摘要 |
PROBLEM TO BE SOLVED: To improve safety of data transmission to a data transmission destination (transmission destination).SOLUTION: A CPU in a file transmission terminal determines whether or not a transmission destination is designated using an IP address (whether or not designated using a host name); transmits a DNS reverse resolution request including the IP address of the transmission destination to a DNS server and receives a DNS reverse resolution response including a host name corresponding to the IP address, when the transmission destination is designated using the IP address; transmits a DNS request including a host name of the transmission destination to the DNS server and receives a DNS response including an IP address corresponding to the host name, when the transmission destination is designated using the host name; and, after that, determines that safety of the transmission destination (domain name, and country/region) is high when a domain name of the transmission destination is registered as a domain name of a secure host and a country/region including the transmission destination is registered as a secure country/region, and permits data transmission to the transmission destination. |
