Tech giant IBM has filed a patent for an Internet of Things[1] (IOT)-focused Blockchain[2] configuration which would tailor the proof-of-work (PoW) protocol in order to address potential security issues in IoT networks, in an application published[3] April 26.
The patent proposes:
“A method, comprising: determining a proof-of-work via an [IOT compatible] device; using a predefined set of nonce values when determining the proof-of-work; storing the proof-of-work on a blockchain; and broadcasting the proof-of-work as a broadcast message.”
Nonces are used in PoW systems[4] to vary the input to a cryptographic hash function so as to obtain a hash that fulfills certain conditions. IBM’s idea to restrict a nonce - literally, a “number that can only be used once” - to a predetermined range could potentially solve two challenges currently facing Blockchain solutions for IoT networks.
IoT devices are embedded with software, sensors and network connectivity, and a Blockchain solution[5] could decentralize the interaction between these devices as well as enable them to execute smart contracts.
Many IoT devices - for example an IP-enabled doorbell of a smart dishwasher - are however “low-power” devices, meaning that they don’t have enough computational power to compete with dedicated mining devices, such as application-specific integrated circuits[6] (ASICs). A network of such devices that would deploy a proof-of-work protocol thus faces a problem of being unable to conduct resource-intensive PoW calculations and at the same time remain secure from malicious external actors, as IBM describes:
“Most IoT devices are constrained in the amount of energy they can consume. To enable such low-power devices to compute proof-of-work for smart contracts, the complexity of a crypto-effort or crypto-puzzle should be reduced. However, reduction in the complexity of
