interception system of Pornographic and virus using of hash value.

A system and a method for intercepting malicious data by using a network device are provided to prevent the installation of a malicious code and virus and to intercept obscene data by being installed at a firewall, a router and a switch. A buffering processing unit(151) buffers the entire or some portion of a file, and a has value generating unit(152) generates a hash value for the file buffered in a firewall device. A hash value database(153) stores/manages the extracted hash value by applying a hash function to the some or entire diversions, malicious codes and viruses. Based on the comparison of the hash value with the hash value of the hash value database, a hash value determining unit(154) judges whether or not the file has the diversions, malicious codes and viruses. According to the judgment, a download blocking unit(155) intercepts the file downloading.