IBM Reimagines Proof-of-Work for Blockchain IoT Devices

IBM is seeking to patent a method for ensuring that a network of connected devices can securely execute blockchain-based smart contracts.

As the tech giant explains in a patent application published Thursday, "one example method of operation may include determining a proof-of-work via a device and 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."

The problem of how to connect Internet of Things (IoT) devices using blockchain has drawn the attention of a number of developers, startups and companies in recent years - indeed, that was the central concept behind IBM's "ADEPT" proof-of-concept, created in partnership with Samsung and unveiled in early 2015.

An IoT-focused blockchain network couldn't engage in the kind of competitive "mining" that powers the bitcoin network, largely because a smart toaster or lightbulb can't harness the power of a warehouse full of specialized computers. At the same time, a large-scale blockchain mine could conceivably have an easier time of attacking a network of IoT devices and, thus, potentially compromise it.

IBM's proposed solution - described in the application - wouldn't ditch bitcoin's proof-of-work system. Proof-of-work adds a block of data - transaction data, in bitcoin's case - to the blockchain by running it through a hash function. This is a simple process; the "work" comes from the requirement to obtain a hash that meets certain parameters, which calls for running the hash function again and again.

Essentially, IBM explains that it would limit the number of nonces, or one-time-use numbers, within a defined range that the IoT-connected devices can employ when updating the conceptual blockchain.

That way, IBM's patent application says, "the complexity of constructing a PoW [proof of work] can be adjusted dynamically, such that there is no incentive for any IoT device to use computing power beyond a determined threshold to increase its chances of a successful completion of a PoW."

This system, the application argues, has the dual benefit: it averts competition among the network's devices for greater and greater computing power, and it prevents an outside actor with a high hash rate from being able to take control of the blockchain. It should, in other words, "provide equal chances of successful completion of proof-of-work to all IoT devices in the network."

IBM envisions applying this invention to smart contracts, with use cases such as "peer to peer (P2P) energy networks, logistic networks, crowd-sourced weather networks, and the like."