Review and Comparison of Lightweight Modifications of the AES Cipher for a Network of Low-Power Devices

In contemporary realities, the development of a smart city and cyber–physical systems is impossible without ensuring their information security. Under conditions of limited resources, it is necessary to maintain a balance between the cryptographic strength of a ciphering algorithm and the requirements it imposes. In this study, we compare lightweight modifications of the Advanced Encryption Standard (AES) symmetric block cipher to determine the most balanced solution for ensuring the confidentiality of information interaction between low-power devices. The comparison is performed with the consideration for both the theoretical parameters determining the cryptographic strength, and encryption and decryption rates, depending on the input data size. Using the results of this investigation, it is concluded that the modified AES is a modification that satisfies most of the imposed requirements. This algorithm outperforms not only other modifications, but also the standard AES; it enhances the values of diffusion and confusion by 5 and 30%, respectively, and it reduces the average encryption/decryption time by a factor of 1.5.