Abstract
Lightweight encryption algorithms are considered a relatively new direction in the development of private key cryptography. This need arose as a result of the emergence of a large number of devices with little computing power and memory. Therefore, it became necessary to develop algorithms that can provide a sufficient level of security, with minimal use of resources. The paper presents a new lightweight LBC encryption algorithm. LBC is a 64–bit symmetric block algorithm. It supports 80 bit secret key. The number of rounds is 20. The algorithm has a Feistel network structure. The developed lightweight algorithm has a simple implementation scheme, and the transformations used in this algorithm have good cryptographic properties. This was verified by studying the cryptographic properties of the algorithm using the "avalanche effect" and statistical tests. The avalanche property was checked for each round when each bit of the source text was changed. Based on the work carried out, it was found that the proposed encryption algorithm is effective to ensure a good avalanche effect and the binary sequence obtained after encryption is close to random. Its security against linear and differential cryptanalysis is also evaluated. The results of the research revealed good cryptographic properties of this algorithm. The algorithm will be used for devices with small hardware resources, in information and communication systems where confidential information circulates, and it is also extremely necessary to exchange information in a protected form in an operationally acceptable time