Researchers at Chiba University in Japan have developed a lightweight algorithm that reorganises blockchain connections to reduce delays in IoT networks.

This study could make blockchain fast enough for time-critical IoT tasks, from sensors to smart infrastructure.

Blockchain is promising for secure data sharing in IoT networks, but existing systems often suffer from high latency that limits time-sensitive applications. Now, researchers have investigated how the structure of peer-to-peer blockchain networks affects IoT-blockchain performance. They developed Dual Perigee, a lightweight peer-selection algorithm that significantly reduces data propagation delays without increasing resource use on IoT devices.

To ensure IoT data are secure and not tampered with, engineers are increasingly turning to blockchain. While often associated with cryptocurrencies, blockchain is essentially a decentralised digital ledger; instead of one company controlling the data, they are shared and maintained collectively across a network of computers.

Unfortunately, existing blockchain systems can be too slow for the split-second decisions required in real-world IoT environments. The primary cause of this sluggishness is not the blockchain protocol itself, but the disorganised way the nodes within peer-to-peer networks communicate. Most previous research has ignored how the overarching shape of these connections – referred to as the network topology – impacts speed in IoT-blockchain systems.

To address this knowledge gap, a research team led by associate professor Kien Nguyen from Chiba University investigated how to streamline operations in IoT-blockchain networks. Their study, published in the journal IEEE Transactions on Network & Service Management (ieeexplore.ieee.org/document/1130184) examines the impact of different network topologies on performance and introduces a method to keep data moving efficiently.

“We aimed to bridge the gap between theoretical design and practical deployment of IoT-blockchain systems by identifying the fundamental causes of their high latency and proposing a decentralised option that is both simple and effective,” said. Nguyen.

First, to understand the root cause of the delays, the researchers implemented a method to generate different network topologies and connect simulated blockchain clients. After analysing various representative cases, they showed the decentralised nature of IoT networks often leads to redundant data transmission. Specifically, they found the current protocols for sharing transactions (the individual data entries) and blocks (the larger bundles of verified records) can cause an exponential increase in data copies. This results in network congestion and queuing delays, particularly when nodes are connected in a way that creates too many overlapping paths.

In response to this problem, the researchers developed Dual Perigee, a lightweight and decentralised algorithm that allows each node to intelligently choose its preferred neighbours in the network. Instead of sticking with a series of random connections, a node using Dual Perigee assigns scores to its peers based on how quickly they deliver both individual transactions and full blocks. If a neighbour is consistently slow, the node automatically disconnects and tries new peers. Over time, the entire network self-organises into a high-speed configuration without needing a central controller.

After testing in a simulated 50-node IoT environment, the algorithm reduced block-related delays by 48.54% compared with the standard approach used in the widely known Ethereum blockchain. It also outperformed state-of-the-art methods, such as the original Perigee algorithm, by over 23%. Notably, the researchers achieved these gains without adding extra computational strain to the IoT devices themselves, as the algorithm relies on passive measurements of data that the devices were already receiving and requires only minimal calculations.

This work has implications across many technological fields. By reducing the time it takes for a blockchain to confirm and share data, the system becomes responsive enough for time-sensitive tasks.

“The proposed decentralised latency-aware peer-selection mechanism can serve as a foundation for future blockchain platforms that support real-time, mission-critical IoT services, ultimately enabling more secure, responsive and trustworthy digital infrastructures,” said Nguyen.

As IoT networks continue to grow in size and complexity, the need for decentralised, trustworthy means of communication will only increase. The research team believes Dual Perigee could play a key role in the near future, as Nguyen said: “Our approach can be applied to emerging IoT-based services that require fast and reliable data sharing, such as smart cities, smart homes, industrial monitoring, healthcare systems and supply-chain tracking.”

The study was co-authored by Koki Koshikawa, Yue Su and Hiroo Sekiya, all from Chiba University (www.chiba-u.ac.jp).