The Study Of Security On Field Data Transmission In Industrial Control System

Industrial control system is most applied in the areas which are beneficial to the people’slivelihood. If the industrial control system is attacked from outside, it may cause a series ofserious consequences, including an environmental disaster, the loss of life, the personal injuryand so on. Those serious consequences may endanger the public life and national security.The technical secrets of product in some industrial production areas are intangible assets,which will cause incalculable economic loss to the enterprise if leaks. Ensuring the security ofinformation in the industrial control system has a very important significance whether to thekey control field or to the general industrial production field.The two kinds of transmission data in industrial control system are field data and controldata. It is not unable to achieve satisfactory results if encrypt the two kinds of data at the sametime. This paper chose to encrypt the field level data. For the high real-time requirementcharacteristic of industrial control system, choosing a high-speed algorithm in encryption anddecryption is very important. And at the same time, the security of algorithm should not beignored. Through comprehensive consideration, a viable hybrid encryption algorithm wasadopted. The main idea of the mixed encryption algorithm is that the field data are encryptedby the DES encryption algorithm which has a fast encryption speed and the key of the DESalgorithm is encrypted by the RSA algorithm which has a higher security. The RSA algorithmhas a higher security but a slow computing speed. Generating large prime numbers processand modular exponentiation operation are the two time-consuming factors. In this paper, theimproved Miller-Rabin algorithm was used in big prime number generation process, and theimproved algorithm of2kband was used in modular exponentiation computation process. Theimproved RSA algorithm has obviously saved the encryption and decryption time. Based onthe hybrid algorithm, an encryption module is designed based on LPC1768. The encryptionmodule is comprised by a network interface, memory interface and a wireless receivinginterface. It is succeed in meeting the industrial control system requirement for data’sacquisition, storage, processing and transmission. In order to verify the correctness of thedecryption process, the Visual Studio2010is used to write encryption interface which willdisplay the data before encryption, after encryption and after decryption.The final test results indicate that the DES-RSA algorithm succeed in encrypting anddecrypting of the data. The total time consumption in the whole process is less than500ms,meeting the real-time requirements of industrial control system. So the hybrid algorithm issuitable for the protection of the field data in the industrial control system.