Cryptography Techniques Within SCADA System-Asurvey

SCADA is abbreviation of “Supervisory Control and Data Acquisition”, the system occupies an important and fundamental aspect today, given the technologies and capabilities in managing and acquisition the most important infrastructures, companies and institutions. These systems were operating in a relatively isolated environment, but due to the evolution in communication systems and the needed to manage resources in real time, the necessity to connect these systems with other communications systems emerged. This trend opened a new aspect that threatens the security of these systems, so these systems are faced numerous and varied attacks from time to time. The main factor in SCADA system is the data and the information, which are exposed to hacking or changing the content of information that transmitted (changing the content of information sometimes creates real risks for the system, and sometimes these risks may be disastrous). Therefore, most of the researches and studies are focus on finding solutions to protect this information. One of these solutions is the cryptography that used in order to encrypt the data that exchanged between channels. The two types of cryptography algorithms which symmetric and asymmetric are used within SCADA system, also the new technologies emerged to integrate more than one crypto algorithm, which the hybrid crypto and cross-crypto algorithm that merge two algorithms in order to get the best features of both algorithms. This paper presents some of important researches highlighted on cryptography techniques that presented in order to get the best security in SCADA communications. A brief summary of the most common researches and studies that deals with the topic of cryptography in SCADA systems, with an explanation of the characteristics, advantages and disadvantage of each one.