Accurate and complete educational records are a valuable asset for people. In recent years, educational records have been digitized. However, there are still two key challenges that have not been resolved. One is to achieve secure and privacy-preserving storage of educational records, while another concern how to realize the sharing of educational records and ensure the security of the sharing process. In this paper, we propose EduRSS, a blockchain-based storage and sharing scheme for educational records is proposed, which combines blockchain, storage servers, and cryptography techniques to create a reliable and safe environment. In our proposal, the blockchain technology is used to ensure the security and reliability of data storage, while the smart contracts on the blockchain are used to regulate the process of storage and sharing. More precisely, the off-chain storage servers store the original educational records in encrypted form, while the hash information of the records is stored on the blockchain. The off-chain records are anchored periodically with the hash information on the blockchain to ensure the security of data storage. Cryptography techniques are utilized to handle records encryption and messages digital signature. To assess the effectiveness of EduRSS, we designed and tested a proof of concept of this scheme. The relative security analysis shows that EduRSS is safe and has a lower computational cost than that of the CP-ABE and the MA-CPABE schemes.

A distributed charging system based on the Internet of Things can provide important supports to ensure the safe and sustainable operation of electric vehicles (EVs). Usually, drivers prefer to use local charging piles by querying the remote cloud server. Frequent communication with the cloud server will not only produce an unnecessary communication overhead but also increase the latency of response. More seriously, the cloud-based centralized management mode is vulnerable to cyber-attacks, which usually leads to privacy leakage. However, previous studies seldom focus on the privacy issue of the charging system for EVs. In this article, a decentralized and privacy-preserving charging scheme for EVs is proposed, which is based on blockchain and fog computing. In this scheme, fog computing is introduced to provide local computing with low latency. Specifically, a fog computing network, which is composed of fog computing nodes (FCNs), is used to provide localized services. Besides, a flexible consortium blockchain architecture is proposed. The blockchain system is deployed on the distributed FCNs, providing a decentralized and secure storage environment. By combining mutual authentication, smart contract, and blockchain-based storage, the security of privacy in the charging process can be ensured. The theoretical analysis and experiments demonstrate the advantages of the proposed scheme.

In recent years, traditional logistics systems are developing toward intelligence based on the Internet of Things (IoT). Sensing devices throughout the logistics network provide strong support for smart logistics. However, due to the insufficient local computing and storage resources of IoT devices, logistics records with sensitive information are generally stored in a centralized cloud center, which could easily cause privacy leakage. In this study, we propose a blockchain-assisted secure storage scheme for logistics data. To be specific, this scheme can be briefly divided into two parts. The first part involves data generation and aggregation, session establishing, records encryption and storage, wherein a blockchain network is used to assist the cloud server with data storage, and smart contracts are deployed to provide reliable storage interfaces. In the second part, an efficient consensus mechanism is introduced to improve the efficiency of the consensus process. Also, the stored records can be securely audited by leveraging the deployed blockchain network. Finally, we analyze the security and privacy properties of this scheme and evaluate its performance in terms of computation and communication overhead by developing an experimental platform. The experimental results indicate that the performance of our scheme is acceptable.

Smart home (s-home) is an important IoT-based application in improving living environment. Many cryptography-based protection schemes have been proposed to guarantee data confidentiality in smart home. Access control is a promising method to protect generated data from unauthorized access, and it is also urgently needed in smart home. Current centralized access control schemes are not excellent in security and performance. For instance, it still faces the problems of single point of failure, low reliability and poor scalability. This study proposes a decentralized and reliable access control scheme for smart home using smart contracts, named DAC4SH. To be specific, this proposed framework consists of APMC (i.e., Access Policies Management Contract), DAMC (i.e., Data Attribute Management Contract), SAMC (i.e., Subject Attribute Management Contract), and DACC (i.e., Data Access Control Contract) for realizing the fine-grained data access control. Meanwhile, we record all the access activities into the immutable distributed ledgers for auditing. To verify the feasibility of our DAC4SH, we construct a Ethereum-based prototype system and evaluate the performance of DAC4SH in terms of computational and communication cost. According to the experimental results, we can conclude that the performance of DAC4SH is appropriate.

With the rapid development of information technology, logistics systems are developing towards intelligence. The Internet of Things (IoT) devices throughout the logistics network could provide strong support for smart logistics. However, due to the limited computing and storage resources of IoT devices, logistics data with user sensitive information are generally stored in a centralized cloud center, which could easily cause privacy leakage. In this paper, we propose Logisticschain, a blockchain-based secure storage scheme for logistics data. In this scheme, the sensing data from IoT devices should be encrypted for fine-grained access control, and a customized blockchain structure is proposed to improve the storage efficiency of systems. Also, an efficient consensus mechanism is introduced to improve the efficiency of the consensus process in the blockchain. Specific to the logistics process, the sensing data generated from IoT devices will be encrypted and aggregated into the blockchain to ensure data security. Moreover, the stored logistics records can be securely audited by leveraging the blockchain network; both IoT data and logistics demands cannot be deleted or tampered to avoid disputes. Finally, we analyze the security and privacy properties of our Logisticschain and evaluate its performance in terms of computational costs by developing an experimental platform.