The Internet of Things (IoT) is gradually transforming the idea of a fully connected world into reality. Billions of physical devices, from tiny sensors to autonomous vehicles and industrial machines, now collect and exchange data online. It is essential to keep this information secure and unchanged, which is why engineers are increasingly exploring blockchain technology. Although blockchain is best known for powering cryptocurrencies, its primary function is much broader. It acts as a decentralized digital ledger where data is shared and maintained across many computers rather than controlled by a single organization.
Despite its security benefits, most blockchain systems operate too slowly for many real-world IoT applications. Smart devices often need to respond in fractions of a second, but current blockchain networks can’t always keep up. Researchers found that the main source of these delays is not the blockchain software itself. Rather, the problem lies in how devices communicate within peer-to-peer networks. In particular, previous studies have largely neglected how the overall structure of these connections, known as network topology, affects the performance of blockchain IoT systems.
Study network design to reduce delays
To address this issue, a research team led by Associate Professor Kien Nguyen from the Institute of Advanced University Research/Graduate School of Computer Science, Chiba University, Japan, examined ways to improve the efficiency of IoT blockchain networks. Their findings were published in IEEE Transactions on Network and Services Management on December 17, 2025. The study analyzes how different network topologies influence speed and introduces a new technique designed to ensure smooth data flow. “Our goal was to bridge the gap between theoretical design and practical deployment of IoT-blockchain systems by identifying the root causes of their high latency and proposing a decentralized solution that is both simple and effective,” explains Dr. Nguyen. The research was co-authored by Koki Koshikawa, Yue Su and Hiroo Sekiya, all of Chiba University.
To identify the cause of the slowdowns, the team created simulations with blockchain clients connected using various network structures. Their analysis found that decentralized IoT networks frequently transmit the same data multiple times. Current methods of sharing transactions (individual data entries) and blocks (larger collections of verified records) can lead to an explosive increase in duplicate copies. As these duplicates propagate through overlapping communication paths, networks become congested and data begins to pile up, significantly increasing delays.
Double perigee allows networks to organize themselves
To solve this problem, the researchers developed a decentralized and lightweight algorithm called “Dual Perigee”. This method allows each device on the network to make smarter decisions about which neighboring devices it connects to. Rather than relying on random connections, a device using Dual Perigee rates its peers based on how quickly they deliver transactions and complete blocks. Consistently slow connections are abandoned and replaced with higher performance connections. Over time, the network naturally reshapes itself to a faster configuration, all without relying on a central authority.
When tested in a simulated 50-node IoT environment, Dual Perigee reduced block delays by 48.54% compared to the standard method used by the Ethereum blockchain. It also outperformed advanced approaches, including the original Perigee algorithm, by more than 23%. It is important to note that these improvements have not increased the workload on IoT devices. The algorithm depends on passive measurements of data already received and requires minimal processing.
Activation of real-time and critical systems
The implications of this work extend to many technological sectors. Faster confirmation and sharing of data allows blockchain systems to support applications where timing is critical. “The proposed decentralized latency-aware peer selection mechanism can serve as a foundation for future blockchain platforms that will support critical IoT services in real-time, thereby enabling more secure, responsive, and reliable digital infrastructures,” explains Dr. Nguyen.
Preparing for the next generation of IoT
As IoT networks continue to grow and become more complex, the demand for decentralized and reliable communication methods will increase. Researchers believe Dual Perigee could play an important role in future technologies. “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,” says Dr. Nguyen.
This research was supported by the Japan Society for the Promotion of Science (JSPS) (grant number: 23H03377) and in part by the Japan Science and Technology Agency (JST) through the establishment of University Scholarships for Creating Scientific and Technological Innovations (grant number: JPMJFS2107).
