Blockchain (BC) technologies have a potential to blend with the existing Internet of things (IoT) platforms. BC enabled IoT platforms
can be offered as a service (BIoTaaS) to provide scalable and trusted new approaches in e.g. IoT device authentication and management, trading with IoT data or in providing reliable and trusted interfaces between Web and smart contracts. At the same time this can lead to a gradual decentralization of highly centralized traditional cloud platforms – a needed change in IoT that can be anticipated from the fog computation and communication architectures, too. Currently the two viable BC candidates for BIoTaaS are the Ethereum (ETH) and the Hyperledger Fabric (HLF). Very diverse applications of BIoTaaS are possible, so it is unlikely that one platform approach or
architecture will be meeting all these needs. Two differentiators have the key impact on selection of BC technology for particular BIoTaaS: existence of need for instant and independent on-chain payments and where the dominant focus is set – on the IoT devices or on the business-to-business (B2B) applications. If the devices are central and payments are required, then ETH BC is the favorite. In case of B2B HLF might be a preferable option due to security features beyond trust, derived from the permissioned network model. Beside the existence of BC, other requirements have to be met for efficient BIoTaaS. We defined a set of such common requirements, which include Web/HTTP/REST and other acknowledgedapplication programming interfaces (API) for entire IoT and BC service access, on-chain smart
contracts, low transaction confirmation delays for instant payments and near real-time operation, and smart oracles for interfacing the off-chain “realworld” objects and systems.

PUSTIŠEK, Matevž, ŠTEFANIČ JUŽNIČ, Leon, KOS, Andrej. Blockchain support in IoT platforms. The IPSI BgD transactions on internet research, ISSN 1820-4503. [Print ed.], Jan. 2018, vol. 14, no. 1.