Blockchain-Based Spatial Registry and Management in Multi-User Mixed Reality

XManuChain: A Permissioned Blockchain Framework for Securing IoP Transactions in Production Process Collaboration

A Rootchain-Centric Hierarchical Multichain Architecture for National Blockchain Infrastructures: Design Rationale and Empirical Evaluation for Mid-Sized Nations With Consolidated Digital Governance

National-scale blockchain infrastructure must simultaneously deliver data residency, auditable governance, and sector-scale performance. Existing large-economy permissioned blockchain designs for national infrastructure, including China’s Blockchain-based Service Network (BSN) and the European Blockchain Services Infrastructure (EBSI), adopt federated or peer-to-peer topologies that suit cross-jurisdictional politics but impose coordination overhead on nations governed under a single administrative domain. This paper proposes, formalizes, and deploys a rootchain-centric hierarchical multichain architecture that powers Vietnam’s national blockchain infrastructure. We build a permissioned Rootchain on Hyperledger Besu with QBFT consensus and operate it as a unified trust anchor and control plane for extensible sector-specific Domain Chains. The Rootchain manages admission, permission registries, audit trails, cross-chain traceability, and verifiable proof-of-control. At its technical core, we introduce a dual-gate authorization algorithm that couples W3C Decentralized Identifiers (DID) and Verifiable Credentials (VC) with on-chain state-proof verification, enabling direct Domain-Chain-to-Domain-Chain interaction without continuous Rootchain round-trips. We further design a Threshold Governance Key (TGK) scheme based on m-of-n multi-signature and hardware security modules that supports emergency actions with on-chain auditability. We implement the architecture and deploy with a geographically distributed testnet of 5, 7, 10, and 14 validators. Our evaluation shows that the Rootchain achieves about 800 write transactions per second with the finality under 3 seconds at the 99th percentile. The testbed shows that the aggregate ecosystem throughput scales proportionally with the number of parallel domain chains, showing the projection of a highly scalable system. Comparative analysis confirms lower governance complexity, faster chain onboarding, and real-time credential revocation versus state-of-the-art national designs, making the architecture suitable for mid-sized nations with consolidated digital governance.

D2S-BFT: A General Performance Evaluation Framework for Sharded Blockchain Networks

Blockchain technology enables decentralized trust, yet traditional blockchain networks face critical scalability limitations under large-scale deployments. Sharding improves throughput through parallel processing, but existing sharded BFT architectures still suffer from severe hierarchical coupling between shards and the verification committee. Moreover, the complex asynchronous competition and backoff/retransmission dynamics in sharded blockchain services remain largely unmodeled, leaving the network-level steady-state behavior of sharded blockchains poorly understood. To address these challenges, we propose D2S-BFT, a novel Decoupled Double-Star Byzantine Fault-Tolerant architecture, which physically decouples local intra-shard consensus from global verification. For rigorous performance evaluation, we establish a randomized-service double-star service system and cast the cross-shard competition mechanism as a finite-source Markov chain. We derive the state transition probability matrix under general load conditions, compute the extended sojourn time, and construct an end-to-end transaction on-chain latency equation that explicitly incorporates encryption overhead, network delay, and queuing delay. The resulting D2S queuing model, expressed in the non-classical Kendall notation L/G/n=2/inf/L-RSS, provides strict theoretical boundary constraints on system performance. It demonstrates that D2S-BFT can effectively alleviate transaction congestion and ensure robust operation, while also laying a rigorous analytical foundation for model-driven configuration optimization in large-scale dynamic blockchain environments.

A Scalable Blockchain Architecture for Digital Certificate Management Using Microservice-Based Processing and Batch Anchoring

Blockchain-based infrastructures have increasingly been adopted for secure and tamper-resistant management of academic credentials. Despite the advantages offered by blockchain technology, existing blockchain-based credential management systems continue to face several scalability challenges, particularly in terms of limited transaction throughput, increased confirmation delays, and continuous ledger growth resulting from storing individual certificates as separate blockchain transactions. These limitations become more evident in large-scale educational environments where universities and affiliated institutions are required to issue and verify thousands of digital credentials within limited operational timeframes. To overcome these challenges, this work introduces a performance-optimized blockchain architecture for scalable academic credential management. The proposed framework separates certificate preprocessing from blockchain anchoring by incorporating a microservice-based parallel processing layer, Merkle-tree-based batch anchoring, and distributed off-chain storage mechanisms. This modular design reduces blockchain transaction overhead while maintaining the security, integrity, auditability, and verifiability of academic credentials. To assess system performance, a formal analytical model integrating queueing theory and blockchain performance characteristics is developed to characterize system behavior under varying workload conditions. By enabling multiple certificates to be aggregated and committed through a single blockchain transaction, the proposed architecture improves throughput and enhances storage efficiency compared to conventional blockchain-based approaches. Analytical evaluation demonstrates that the system can sustain high certificate issuance rates while maintaining low confirmation latency and minimal on-chain storage growth.

A Requirement-Driven Expert System for Blockchain Consensus Mechanism Selection

Blockchain technology has introduced a rapidly expanding range of consensus mechanisms, each designed to satisfy different operational requirements related to security, scalability, decentralization, transaction throughput, and energy efficiency. Selecting an appropriate consensus mechanism has consequently become a complex multi-criteria decision problem, particularly for developers and organizations without extensive expertise in distributed systems and blockchain architectures. Existing tools primarily address protocol benchmarking and static documentation, leaving the decision-support dimension largely unaddressed. This paper presents a web-based expert system designed to support the selection of blockchain consensus mechanisms according to specific user-defined operational requirements. The proposed solution was implemented using the MERN technology stack, consisting of MongoDB, Express.js, React, and Node.js, enabling a modular and scalable architecture suitable for future expansion and maintenance. The recommendation process is based on a two-phase filtering and scoring algorithm. In the first phase, mechanisms incompatible with mandatory user-defined constraints, including network type and key resource type, are systematically eliminated. In the second phase, the remaining mechanisms are ranked using attribute matching across criteria encompassing energy efficiency, scalability, security, decentralization, and transaction speed. The system returns the three most suitable consensus mechanisms for the given operational scenario together with their key characteristics. In addition to recommendation functionality, the application supports user authentication, recommendation history management, and administrative maintenance of the consensus mechanism database, which currently contains 38 distinct blockchain consensus protocols. Experimental evaluation through twelve representative usage scenarios demonstrated that the system consistently produces contextually relevant recommendations aligned with user-specified requirements. A comparative analysis with existing tools confirms that the proposed system occupies a distinct decision-support role currently absent from the available tooling landscape. A comparative analysis against four representative existing tools indicates that the proposed system combines a set of decision-support capabilities not jointly offered by any one of them. The presented approach contributes a transparent and extensible decision-support framework intended to simplify architectural planning and management of blockchain-based distributed systems.

GovChain: An Affordable Cloud Security Framework for Developing Nations – A Model for Citizen-Centric E-Governance

Cloud computing has become a key platform for modern e-governance systems. It helps governments to provide services like digital identity management, welfare distribution, and land record administration. It handles large amounts of sensitive citizen data, so keeping data accurate and transparent is essential. Blockchain technology ensures data cannot be changed easily and is resistant to tampering. However, typical blockchain systems require a lot of computational power and often face delays because each transaction needs consensus operations. This paper presents GovChain, a lightweight blockchain framework that aims to overcome these challenges in settings with limited resources. The model introduces a Lazy Hashing mechanism, which separates transaction recording from consensus validation. Updates are first saved in a temporary structure called the Dirty Tree. Here, state commitments are created right away, while consensus checks happen periodically in the background. This method lowers infrastructure costs and processing delays, all while ensuring reliable data integrity. Experimental tests using a cloud-based prototype show that Gov Chain achieves low transaction latency of 0.2 to 0.4 seconds, minimal computational overhead of under 3%, and better throughput as compared to traditional blockchain systems. The findings indicate that Gov Chain offers a practical and scalable solution for secure and citizen-focused e-governance systems in developing countries.