SMChain: A Scalable Blockchain Protocol for Secure Metering Systems in Distributed Industrial Plants

Metering is a critical process in large-scale distributed industrial plants, which enables multiple plants to collaborate to offer mutual services without outside interference. When distributed plants measure the data from a shared common source, e.g., flow metering in an oil pipeline, trustworthiness and immutability must be guaranteed among them. In this paper, we propose a hierarchical and scalable blockchain-based secure metering system, \textit{SMChain}, to provide strong security, trustworthy guarantee, and immutable services. {\em SMChain} adopts a two-layer blockchain structure, consisting of independent local blockchains stored at individual plants and one state blockchain stored in the cloud. To deal with the scalability issues within each plant, we propose a novel scalable Byzantine Fault Tolerance (BFT) consensus protocol based on \textit{(k, n)}-threshold signature scheme to deal with the Byzantine faults and reduce the intra-plant communication complexity from $O(n^2)$ to $O(n)$. For the state blockchain, we use a cloud-based service to synchronize and integrate the local blockchains into one state blockchain, which can further be distributed back to each plant

ChainSplitter: Towards Blockchain-based Industrial IoT Architecture for Supporting Hierarchical Storage

The fast developing Industrial Internet of Things (IIoT) technologies provide a promising opportunity to build large-scale systems to connect numerous heterogeneous devices into the Internet. Most existing IIoT infrastructures are based on a centralized architecture, which is easier for management but cannot effectively support immutable and verifiable services among multiple parties. Blockchain technology provides many desired features for large-scale IIoT infrastructures, such as decentralization, trustworthiness, trackability, and immutability. This paper presents a blockchain-based IIoT architecture to support immutable and verifiable services. However, when applying blockchain technology to the IIoT infrastructure, the required storage space posts a grant challenge to resource-constrained IIoT infrastructures. To address the storage issue, this paper proposes a hierarchical blockchain storage structure, \textit{ChainSplitter}. Specially, the proposed architecture features a hierarchical storage structure where the majority of the blockchain is stored in the clouds, while the most recent blocks are stored in the overlay network of the individual IIoT networks. The proposed architecture seamlessly binds local IIoT networks, the blockchain overlay network, and the cloud infrastructure together through two connectors, the \textit{blockchain connector} and the \textit{cloud connector}, to construct the hierarchical blockchain storage. The blockchain connector in the overlay network builds blocks in blockchain from data generated in IIoT networks, and the cloud connector resolves the blockchain synchronization issues between the overlay network and the clouds. We also provide a case study to show the efficiency of the proposed hierarchical blockchain storage in a practical Industrial IoT case

SoK: Sharding on Blockchain

Blockchain is a distributed and decentralized ledger for recording transactions. It is maintained and shared among the participating nodes by utilizing cryptographic primitives. A consensus protocol ensures that all nodes agree on a unique order in which records are appended. However, current blockchain solutions are facing scalability issues. Many methods, such as Off-chain and Directed Acyclic Graph (DAG) solutions, have been proposed to address the issue. However, they have inherent drawbacks, e.g., forming parasite chains. Performance, such as throughput and latency, is also important to a blockchain system. Sharding has emerged as a good candidate that can overcome both the scalability and performance problems in blockchain. To date, there is no systematic work that analyzes the sharding protocols. To bridge this gap, this paper provides a systematic and comprehensive review on blockchain sharding techniques. We first present a general design flow of sharding protocols and then discuss key design challenges. For each challenge, we analyze and compare the techniques in state-of-the-art solutions. Finally, we discuss several potential research directions in blockchain sharding

Chord-based Key Establishment Schemes for Sensor Networks

Abstract — Because of limited resources at sensor nodes, sensor networks typically adopt symmetric-key algorithms to provide security functions such as protecting communications between nodes. In order to use symmetric-key algorithms, two nodes need to establish a secret session key first. In this paper, we propose a novel chord-based key establishment (CBKE) protocol that allows any pair of nodes in a sensor network to establish a secret session key. CBKE is a generalized deterministic key establishment scheme that provides great flexibility for balancing memory overhead, reliability, and communication cost. We analyze the properties of CBKE and explore the performance tradeoffs using simulation. 1

Implementation complexity of bit permutation instructions

Abstract- Several bit permutation instructions, including GRP, OMFLIP, CROSS, and BFLY, have been proposed recently for efficiently performing arbitrary bit permutations. Previous work has shown that these instructions can accelerate a variety of applications such as block ciphers and sorting algorithms. In this paper, we compare the implementation complexity of these instructions in terms of delay. We use logical effort, a process technology independent method, to estimate the delay of the bit permutation functional units. Our results show that for 64-bit operations, the BFLY instruction is the fastest among these bit permutation instructions; the OMFLIP instruction is next; and the GRP instruction is the slowest. I