The demands on Internet of Things (IoT) technologies have grown rapidly due to the various application fields and the advancements in wireless communications technologies [1], [2]. The term things in the Internet of Things is a piece of equipment having a sensing, actuating, storage, or processing capability. These devices possess unique characteristics, i.e., little memory, reduced battery capacity, and limited processing power [3]. The IoT has great potential to impact our lives in the future. From home automation to healthcare systems, the IoT has numerous applications to improve industries and society by enabling smart communication between objects and devices in a cost-effective manner [4], [5]. Therefore, it is predicted that there will be about 50 billion IoT devices by 2050 [6]. Due to the expansion of IoT networks in the last decade, various hardware platforms have been developed to support IoT sensors and actuators. Similarly, a number of operating systems (OSs) have gradually been developed to run these tiny sensors [7]. Various IoT communications standards have emerged from different organizations. For example, the Internet Engineering Task Force (IETF) [8], the International Telecommunication Union-Telecommunication (ITU-T) [9], the Institute of Electrical and Electronics Engineers (IEEE), the European Telecommunications Standards Institute (ETSI) [10], the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) [11], One Machine-to-Machine (M2M) [12] and the 3rd Generation Partnership Project (3GPP) [13] are actively working to provide efficient IoT communications protocols. The IETF currently has various working groups (WGs) that deal with IoT-related protocols on any layer above the link layer (e.g., at the network layer). The IETF Routing over Lossy and Low-Power Network (ROLL) WG (RFC 6550) [14] is focused on providing standardization of the IPv6 Routing Protocol for Low-Power and Lossy Networks (RPL). Similarly, the IETF IPv6 over Low-Power Wireless Personal Area Networks (6LoWPAN) (RFC 4944) [15] works on IPv6 networking protocol optimization using IEEE 802.15.4. The IETF 6loBAC WG (RFC Ed Queue) [16] provides specifications for transmission of IPv6 packets on master-slave/token-passing (MS/TP) networks. The IETF 6TiSCH Operation Sublayer (6TOP) WG (RFC Ed Queue) [17] defines the mode of operation for IPv6 using an IEEE 802.15.4e (6TiSCH) network. Datagram Transport Layer Security (DTLS) in a Constrained Environment (DICE) was drafted by the IETF WG DICE (RFC 7925) [18]. At the application layer, the IETF Constrained Application Protocol (CoAP, RFC 7252) provides web services to constrained devices [19]. Concise Binary Object Representation (CBOR, RFC 7049) provides binary representation of structured data [20]. The Object Signing and Encryption (COSE) WG (RFC Ed Queue) focuses on creating CBOR-based signing and encryption formats [20]. Application layer security for data exchange with CoAP using the COSE format is provided by IETF’s Object Security of CoAP (OSCoAP, RFC 7744) [21].