Switch which carries out encrypted transmission according to fields

The invention discloses a switch which carries out encrypted transmission according to fields. The realization process comprises following steps that an interference module is added to the switch; when the switch transmits messages in a subnetwork, encryption is carried out according to the fields; different encryption modes are used according to different fields; correspondingly, a descrambling module is installed on the network card of an outer network which receives the information; after the descrambling module restores the encrypted information into the correct messages, the messages are reported to a transmission layer for transmission. Compared with the prior art, the switch which carries out encrypted transmission according to fields has the advantages that an inner anti-eavesdrop function is realized, the application demands of occasions which have high information security demands and need to prevent inner eavesdroppers can be satisfied, and the switch is strong in practicability and easy in popularization.