Vol.:(0123456789) 1 3 Journal of Ambient Intelligence and Humanized Computing https://doi.org/10.1007/s12652-020-01694-9 ORIGINAL RESEARCH LRBC: a lightweight block cipher design for resource constrained IoT devices A. Biswas 1  · A. Majumdar 1  · S. Nath 1  · A. Dutta 2  · K. L. Baishnab 1 Received: 3 August 2019 / Accepted: 3 January 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract The internet of things (IoT) is now an in-demand technology that has been adopted in various applications and includes vari- ous embedded devices, sensors and other objects connected to the Internet. Due to the rapid development of this technology, it covers a signifcant portion of the research interests nowadays. IoT devices are typically designed for collecting diferent types of data from various sources and transmitting them in digitized form. However, data security is the burning issue in the IoT technology, which can broadly impact the privacy of crucial data. In this regard, a new lightweight encryption method called LRBC has been proposed in this work for resource constraint IoT devices which can provide data security at the sensing level. The LRBC has used the structural advantages of both substitution–permutation network (SPN) and Feistel structure together to achieve better security. Furthermore, the proposed method has been tested on NEXYS 4 DDR FPGA (Artix-7) trainer kit and implemented for application specifc integrated circuit (ASIC) chip on TSMC 65 nm technology. The proposed algorithm consumes very less power of 11.40 μW and occupies a 258.9 GE (Gate Equivalent) area. Besides, a thorough security analysis shows that the proposed scheme ensures high security against various attacks with robustness. Moreover, the average avalanche efect of LRBC is found to be 58% and 55.75% concerning plaintext and key, respectively. Keywords Lightweight encryption · IoT · Block cipher · FPGA · ASIC chip 1 Introduction Internet of things (IoT) is the extremely focused research topic that has revolutionized the life of human beings through its ability to provide numerous advanced comput- ing facilities at the doorstep. The word ‘things’ in IoT refers to a physical object that has a unique identifer or an embed- ded system with processing and automatic data transmission capability dedicated to a specifc task. It has the potential to form a competent and ubiquitous connectivity between all the physical objects around us and the digital world. The whole world is currently witnessing a remarkable growth in IoT deployments and solutions. IoT directs the modern world to become smarter progressively through diferent challeng- ing application areas such as smart healthcare (Majumdar et al. 2018a, b), smart agriculture (Ray 2017), smart energy grids (Majumdar et al. 2018a, b), home and building auto- mation (Hui et al. 2017), smart trafc (Zhou et al. 2017) etc. In this new world of data, IoT is quickly expanding; however due to insufcient security and privacy measures its sustainable development can be afected a lot. Typically, IoT devices are responsible for collecting diferent types of sensed data through various sensors, out of them some may be highly confdential to the user’s perspective and should not be revealed to others. As per the various industry sur- vey, security is the most promising concern for industrial IoT users today. So, it is utmost necessary to integrate more security features in both the hardware and the device soft- ware to enhance the IoT device layer security and ensure the protection of crucial sensed information. In this ven- ture, incorporating the cryptography concept at the physical constraints of IoT devices can be a favorable option. Data encryption at IoT devices before transmitting to back-end systems (cloud server) using cryptographic algorithms can help to maintain data integrity and inhibit data snifng by hackers. Though cryptography based security is increasingly important, supporting diferent cryptographic algorithms * A. Biswas arpita.nits@ieee.org 1 Department of Electronics and Communication Engineering, NIT Silchar, Silchar, India 2 Department of Electronics and Communication Engineering, Assam University, Silchar, India