An Efficient Lightweight Cryptography Algorithm to Ensure Data Confidentiality in IoMT Devices

Cyber-attacks may target data collected from devices on the Internet of Medical Things (IoMT) systems that use very sensitive data. To stop illegal access, data misuse, data monitoring, and data alteration, security is crucial while considering a network. More and more data breaches on these devices implemented stronger encryption techniques. These devices lack the resources necessary to implement algorithms for classical cryptography. One method that has been investigated and developed to address this problem is lightweight cryptography. It's a low computational complexity or tiny footprint encryption technique. A lightweight cipher primarily used for data encryption and data authentication which has to be deployed in IoMT applications is proposed. The main challenge while designing an efficient cryptography algorithm for IoMT devices is to achieve optimal cost and performance without compromising on security. Lightweight cryptography algorithms are the only algorithms that can be efficiently used in these devices because of their extremely low demand for resources and power consumption making them extremely fast in operation. The paper proposes ATOM, a new symmetric lightweight block cipher following the Substitution-Permutation Network structure for authentication and encryption in lightweight devices having a variable key size of 64-bits and 128-bits, alterable number of rounds of 5 and 9, processing a plaintext of size 64-bits to output a ciphertext of size 64-bits. By this, we can ensure end-to-end secure transmission of data in IoMT devices.