A search for a convenient data encryption algorithm - For an Internet of Things device
Olgeir Gunnsteinsson · Chalmers Publication Library (Chalmers University of Technology) · 2016
Nowdays, the number of IoT (Internet of Things) devices are growing rapidly around the world with wide range of purposes.Many types of these devices collect data and depending on their purpose, some of the data can be highly sensitive for the user.This calls for security on the device which has to secure the collected data and send it to a server through the Internet.Using TLS (Transport Layer Security) is a great way to provide such a security and one part of it is the data encryption which is the main focus of this thesis.The problem is that IoT devices are often made out of microprocessors having a low computational power and performance.The main goal of this thesis is to find the most suitable data encryption algorithm for a small 32-bit CPU hardware with requirements of good speed performance, security and space complexity using a specific encryption library from ARM mbed.The four most popular symmetric encryption algorithms DES (Data Encryption Standard), 3DES (Triple DES), AES (Advanced Encryption Standard-Rijndael) and Blowfish from the library are going to be compared in order to find the most suitable one for a mid-high end IoT device.Then the most suitable block cipher mode of operation, the ECB (Electronic Codebook), CBC (Cipher Block Chaining), OFB (Output Feedback), CFB (Cipher Feedback) or CTR (Counter) are compared to find the one that fits the task the best.Based on literature studies, it is shown that the AES-128-bits using CTR cipher block model provides the best speed performance and security on the device.