Patent ID: 8195816

Claim:
A security management device comprising: a first database that stores domain names and IP addresses of sites, an access to which is confirmed as permissible, in association with each other; a second database that stores domain names and IP addresses of sites, an access to which is confirmed as not permissible, in association with each other; a third database that stores identification information of a plurality of DNS servers meeting predetermined security standards, the third database being protected by a network security feature for preventing DNS cache poisoning; a communication interface configured to receive from a communication terminal a domain name and an IP address of a site; and a processor configured to: check whether a combination of the domain name and the IP address is registered in either the first database or the second database; if the combination is registered in the first database, permit an access by the communication terminal to the site; if the combination is registered in the second database, inhibit an access by the communication terminal to the site; if the combination is not registered in either the first database or the second database, check whether the combination is registered in at least one of the plurality of DNS servers whose identification information is registered in the third database; if the combination is registered in the at least one DNS server, permit an access by the communication terminal to the site; and if the combination is not registered in the at least one DNS server, inhibit an access by the communication terminal to the site.