Blockchains, Volume 3, Issue 4 (December 2025) – 4 articles

Trust in financial institutions hinges on the ability to prove solvency, yet recent crises have exposed the limits of audits and opaque governance. We introduce a practical protocol that enables crypto-exchanges and other financial actors to demonstrate real-time solvency without continuous third-party oversight, while preserving transparency and regulatory alignment. Complemented by a Particles model that fragments transactions to protect privacy and enhance liquidity, this framework integrates solvency, privacy, and governance into a unified standard. We argue that it represents a potential revolution in the financial industry. Full article

This study addresses critical challenges in managing the transportation of spent nuclear fuel, including inadequate data transparency, stringent confidentiality requirements, and a lack of trust among collaborating parties—issues prevalent in traditional centralized management systems. Given the high risks involved, balancing data confidentiality with regulatory transparency is imperative. To overcome these limitations, a technical framework integrating blockchain technology and the Internet of Things (IoT) is proposed, featuring a multi-tiered consortium chain architecture. This system utilizes IoT sensors for real-time data collection, which is immutably recorded on the blockchain, while a hierarchical data structure (operational, supervisory, and public layers) manages access for diverse stakeholders. This approach significantly enhances data immutability, enables real-time multi-sensor data integration, improves decentralized transparency, and increases resilience compared to traditional systems. It should be noted that the proposed framework is a theoretical study and has not yet been implemented or empirically validated, with practical deployment reserved for future work. Ultimately, this blockchain-IoT framework improves the safety, transparency, and efficiency of spent fuel transportation, effectively resolving the conflict between confidentiality and transparency in nuclear data management and offering significant practical implications. Full article

Blockchain is an emerging technology that is being used to create innovative solutions in many areas, including healthcare. Nowadays healthcare systems face challenges, especially with security, trust, and remote data access. As patient records are digitized and medical systems become more interconnected, the risk of sensitive data being exposed to cyber threats has grown. In this evolving time for healthcare, it is important to find a balance between the advantages of new technology and the protection of patient information. The combination of blockchain–InterPlanetary File System technology and conventional electronic health record (EHR) management has the potential to transform the healthcare industry by enhancing data security, interoperability, and transparency. However, a major issue that still exists in traditional healthcare systems is the continuous problem of remote data unavailability. This research examines practical methods for safely accessing patient data from any location at any time, with a special focus on IPFS servers and blockchain technology in addition to group signature encryption. Essential processes like maintaining the confidentiality of medical records and safe data transmission could be made easier by these technologies. Our proposed framework enables secure, remote access to patient data while preserving accessibility, integrity, and confidentiality using Ethereum blockchain, IPFS, and group signature encryption, demonstrating hospital-scale scalability and efficiency. Experiments show predictable throughput reduction with file size (200 → 90 tps), controlled latency growth (90 → 200 ms), and moderate gas increase (85k → 98k), confirming scalability and efficiency under varying healthcare workloads. Unlike prior blockchain–IPFS–encryption frameworks, our system demonstrates hospital-scale feasibility through the practical integration of group signatures, hierarchical key management, and off-chain erasure compliance. This design enables scalable anonymous authentication, immediate blocking of compromised credentials, and efficient key rotation without costly re-encryption. Full article

The electronic judicial evidence preservation systems face various challenges including regulatory control, data exchange, poor credibility, etc. To address these issues, a blockchain-based judicial evidence preservation framework, JudicBlock, is proposed in the present study. It combines the scalability of the Interplanetary File System with the transparency and security of public blockchain. By decentralizing data management and using cryptographic integrity, the system ensures reliable chronological tracking of investigative changes. Unlike traditional approaches, JudicBlock incorporates smart contracts and advanced consensus mechanisms to enforce strict access controls with secure collaboration among the stakeholders. The simulation results show that JudicBlock provides better results over traditional ELR (electronic law records) storage schemes in terms of mining cost, query fetching time, block processing IPFS (Interplanetary file systems) throughput, etc. At a USD 6 mining cost, it appends an average of 23,601 transactions. For 25 blocks, the average query fetching time is 0.852 ms with the cache support of 32 KB. The proposed scheme achieves an average ELR uploading latency improvement of 6.79% over traditional schemes. The results indicate the efficacy of the proposed scheme over the conventional schemes. Full article