# SIT: A Lightweight Encryption Algorithm for Secure Internet of Things

## TL;DR

This paper introduces SIT, a lightweight 64-bit block cipher designed for IoT devices, balancing security and efficiency by using a simplified architecture suitable for low-power, constrained hardware.

## Contribution

It presents a novel lightweight encryption algorithm combining Feistel and substitution-permutation network structures optimized for IoT devices.

## Key findings

- Provides substantial security with only five encryption rounds
- Demonstrates efficient hardware implementation on an 8-bit micro-controller
- Achieves favorable code size, memory use, and cycle performance compared to benchmarks

## Abstract

The Internet of Things (IoT) being a promising technology of the future is expected to connect billions of devices. The increased number of communication is expected to generate mountains of data and the security of data can be a threat. The devices in the architecture are essentially smaller in size and low powered. Conventional encryption algorithms are generally computationally expensive due to their complexity and requires many rounds to encrypt, essentially wasting the constrained energy of the gadgets. Less complex algorithm, however, may compromise the desired integrity. In this paper we propose a lightweight encryption algorithm named as Secure IoT (SIT). It is a 64-bit block cipher and requires 64-bit key to encrypt the data. The architecture of the algorithm is a mixture of feistel and a uniform substitution-permutation network. Simulations result shows the algorithm provides substantial security in just five encryption rounds. The hardware implementation of the algorithm is done on a low cost 8-bit micro-controller and the results of code size, memory utilization and encryption/decryption execution cycles are compared with benchmark encryption algorithms. The MATLAB code for relevant simulations is available online at https://goo.gl/Uw7E0W.