Performance analysis of data security algorithms used in the railway traffic control systems

First of all, the railway traffic control process should ensure the safety. One of the current research areas is to ensure the security of data in the distributed rail traffic control systems using wireless networks. Emerging security threats are the result of, among others, an unknown number of users who may want to access the network, and an unknown number and type of equipment that can be connected to the network. It can cause potential threats resulting from unknown format of data and hacker attacks. In order to counteract these threats, it is necessary to apply safety functions. These functions include the use of data integrity code and encryption methods. Additionally, due to character of railway traffic control systems, it is necessary to keep time determinism while sending telegrams. Exceeding the maximum execution time of a cryptographic algorithm and creating too large blocks of data constitute two critical factors that should be taken into account while developing the system for data transmission. This could result in the inability to transmit data at a given throughput of the transmission channel (bandwidth) at a certain time. The paper presents analysis of delays resulting from the realization of safety functions: such as to prepare the data for transfer and their later decoding. Following block encryption algorithms have been analyzed: Blowfish, Twofish, DES, 3DES, AES-128, AES-192 and AES-256 for modes: ECB, CBC, PCBC, CFB, OFB, CTR and data integrity codes: MD-5, SHA-1, SHA-224, SHA-256, SHA-384, SHA-512, SHA-512/224 and SHA-512/256. The obtained results can be very helpful in the development of new rail traffic control systems in which wireless data transmission is planned.