In the Internet of Things (IoT) everything will be connected, from refrigerators to coffee machines, to shoes. Many such “things” will have a very limited amount of energy to operate, often harvested from their own environment. Providing data confidentiality for such energy-constrained devices has proven to be a hard problem. In this article, we discuss existing approaches to data confidentiality for energyconstrained devices and propose a novel approach to drastically reduce a node's energy consumption during encryption and decryption. In particular, we propose to distribute encryption and decryption computations among a set of trusted nodes. We validate the proposed approach through both simulations and experiments. Initial results show that the proposed approach leads to energy savings (from a single node's perspective) of up to 73% and up to 81% of the energy normally spent to encrypt and decrypt, respectively. With such great savings, our approach holds the promise to enable data confidentiality also for those devices, with extremely limited energy, which will become commonplace in the IoT.

Chapter Contents:

• 5.1 Introduction
• 5.2 Data confidentiality in the IoT
• 5.3 A distributed computation approach
• 5.4 Arduino-based experimental analysis
• 5.4.1 Testbed setup
• 5.4.2 Experimental measurements
• 5.4.2.1 Energy measurements
• 5.4.2.2 Lifetime increase: a single node's perspective
• 5.4.2.3 Lifetime increase: a multi-hop network perspective
• 5.4.2.4 Battery discharging profile
• 5.5 Zolertia-based simulation analysis
• 5.5.1 Simulator setup
• 5.5.2 Simulation results
• 5.6 Conclusions and future work
• References

Inspec keywords: telecommunication power management; cryptography; Internet of Things; energy conservation

Other keywords: energy savings; decryption computations; energy-constrained devices; IoT; distributed approach; encryption computations; energy consumption; coffee machines; trusted nodes; energy-efficient data confidentiality; Internet of Things

Subjects: Data security; Computer communications; Cryptography; Energy conservation; Telecommunication systems (energy utilisation); Computer networks and techniques