Sensor systems and Internet of Things (IoT) environments raise a new major challenge to security. Some of these issues can be solved with blockchain protocols, for example, distributed ledger technologies (DLTs); however, “it is still not clear whether blockchain protocols can be implemented efficiently on resource-constrained IoT devices.”

The paper shows an example of a secure IoT device with IOTA functionalities: an IOTA light node based on STM32, with all communication functions, cryptographic functions, and IOTA operations. ARM Cortex-M controllers allow up to 22 times faster performance. The examined solution uses a new approach based on trits = -1, 0, 1 and trytes. The proposed light node is done with “the STM32 boards Nucleo-F746ZG and Nucleo-F429ZI, both equipped with an Ethernet module.”

The presented solution’s security aspects are given in section 2.2. A noted limitation of this solution: each transaction must contain a computed proof-of-work (PoW) nonce; however, this cannot be done quickly enough, so there is a need to find other possibilities.