Industrial Ethernet-based Control Data Encryption Research

Ethernet is a standard of connecting computers with the LAN and a communication protocol by which net devices exchange data. In order to make the best economy benefit, by using automation technology, the enterprise hopes that the whole factory should conform as one system. According to the requirement, many kinds of industrial fieldbus come into being. Industrial Ethernet, one kind of these new fieldbus, is a result of combining two technologies: Ethernet and TCP/IP. Comparing with the traditional fieldbus, industrial Ethernet has more advantages, such as more compatible, relatively simple in the configuration of the protocol, more stable and more reliable. So the industrial Ethernet could bring us much more convenience and then receive broad acceptance. At the same time, because of the opening of the industrial Ethernet, it also have to face the same security problems the commerce net often encounters, such as virus, illegal invasion, illegal operation and so on. Then the corresponding measure, encrypting the data in the industrial Ethernet, emerges as the times require. The controlling data, relating to the safe running of the field devices, are more necessary to encryption.Based on the specialties of the industrial Ethernet, emphasizing the real time of the data transfer and maintaining the low quantity of the data transfer, the paper chooses the controlling data as the encrypting object and designs a project which is appropriate for the controlling data communicated in the industrial Ethernet.Nowadays, High Speed Ethernet (HSE) is one of the pivotal technologies that our country stresses on the industrial Ethernet. In order to provide the platform of implementing the encrypting project, the paper analyzes the structure of the HSE protocol and realizes the important layer-SMPM. Then the paper puts forward a blending encryption project: using the AES algorithm to encrypt the controlling data, using the RSA algorithm to transfer the key of the AES algorithm. And someimprovements are applied in the project to accelerate the encrypting speed and enhance the transfer security, such as improving the AES algorithm, using MD5 algorithm to make a digital signature to prevent data from being tampered, adding the identity recognizing code to prevent the message from being forged. Finally, the paper does some quantification test to make sure that the project would not affect the real time communication in the industrial Ethernet.