Synopsis: a Scalable Byzantine Distributed Ledger for IoT Networks

Blockchain technology is a distributed ledger system designed to securely process and store data. Although it offers several advantages when the number of participants increased, bolckchain will suffer from significant scalability challenges, such as the case of Internet of Things (IoT) networks. To address the specific needs of IoT, it is necessary to redesign consensus mechanisms and block formation processes. In this paper, we introduce Synopsis, an innovative hierarchical blockchain framework. Synopsis introduces a wireless-optimized Byzantine chain replication protocol and a novel probabilistic data structure. Both are designed to enhance locality and hierarchy, thereby improving system reliability and performance. We implemented Synopsis and evaluated its performance through extensive simulations and real-world testbed experiments. Our findings show that Synopsis effectively reduces the memory usage from Megabytes to just a few Kilobytes, achieving a 1000 time improvement. Synopsis also significantly decreases message complexity by 85% and commitment delay by 99.4%.