How Does Encryption Influence Timing in IoT?

In the past few years, the Internet of Things (IoT) has taken the attention across the world. IoT has the power to change our daily lives. While we are starting to see its incredible impact, security issues may represent the greatest obstacle to growth. The IoT security is a bit more challenging than traditional network security because of the differences in standards, device capabilities, and communication protocols. Lightweight encryption algorithm is a relevant security solution for the resource-constrained devices in IoT. Thus, timing is affected by such algorithms. In this paper, the impact of the IoT encryption algorithms on timing is evaluated throughout real experimental tests. The results show that when a 128-bit key size is utilized Cipher-Block Chaining (CBC) encryption took 1.24x longer than Counter (CTR) and 2.54x longer than Electronic Codebook (ECB); CBC decryption took 5.08x longer than CTR and 3.71x longer than ECB. These numbers were very similar or higher in 192 and 256-bit key sizes.