Privacy-Preserving Searchable Encryption Scheme Based on Public and Private Blockchains

While users enjoy the convenience of data outsourcing in the cloud,they also face the risks of data modification and private information leakage.Searchable encryption technology can perform keyword searches over encrypted data while protecting their privacy and guaranteeing the integrity of the data by verifying the search results.However,some associated problems are still encountered,such as the low efficiency of verification and uncontrollable query results.Accordingly,this paper proposes a Privacy-Preserving Searchable Encryption(PPSE)scheme based on public and private blockchains.First,we store an encrypted index in a private blockchain while outsourcing corresponding encrypted documents to a public blockchain.The encrypted documents are located through the encrypted index.This method can reduce the storage overhead on the blockchains,and improve the efficiency of transaction execution and the security of stored data.Moreover,we adopt a smart contract to introduce a secondary verification access control mechanism and restrict data users’access to the private blockchain through authorization for the purpose of guaranteeing data privacy and the correctness of access control verification.Finally,the security analysis and experimental results indicate that compared with existing schemes,the proposed scheme can not only improve the security of encrypted data but also guarantee the efficiency of the query.

Blockchain for Education:Verification and Management of Lifelong Learning Data

In recent years,blockchain technology has been applied in the educational domain because of its salient advantages,i.e.,transparency,decentralization,and immutability.Available systems typically use public blockchain networks such as Ethereum and Bitcoin to store learning results.However,the cost of writing data on these networks is significant,making educational institutions limit data sent to the target network,typically containing only hash codes of the issued certificates.In this paper,we present a system based on a private blockchain network for lifelong learning data authentication and management named B4E(Blockchain For Education).B4E stores not only certificates but also learners’training data such as transcripts and educational programs in order to create a complete record of the lifelong education of each user and verify certificates that they have obtained.As a result,B4E can address two types of fake certificates,i.e.,certificates printed by unlawful organizations and certificates issued by educational institutions for learners who have not met the training requirements.In addition,B4E is designed to allow all participants to easily deploy software packages to manage,share,and check stored information without depending on a single point of access.As such,the system enhances the transparency and reliability of the stored data.Our experiments show that B4E meets expectations for deployment in reality.

Blockchain Management in Smart Grid

Power Supply and Smart Grid represent specific business,which must be managed by permissioned(private)blockchain.Despite its disadvantages-time consuming,expensive,and losing from network effect-the permissioned blockchain offers balance,guarantees stability,and provides physical limitations for usage of validating nodes only in the network.The management of permissioned blockchain is necessary for tracing the processes in it.The author has represented the moment following topics:the idea for applying blockchain in business environment,blockchain technology-as a linked list with a new key on each step,node structure and information models for node management with a large granularity,detail models for node management with accent on configuration and performance and managed objects classes for installation of blockchain network with accent on security and performance,models for blockchain network management and five scenarios for blockchain transactions management.The paper represents a stage of project Blockchain in Smart Grid:describing of Managed Objects classes for functional areas of blockchain life cycle:Provision,Configuration,Maintenance,Security(developed),Accounting,Performance,and Subscriber control.The author uses the life cycle of telecommunications networks as a reference.The models are designed for user interface developers,university professors,and students.

Hyperledger Fabric Blockchain: Secure and Efficient Solution for Electronic Health Records

Background:Electronic Health Record(EHR)systems are used as an efficient and effective technique for sharing patient’s health records among different hospitals and various other key stakeholders of the healthcare industry to achieve better diagnosis and treatment of patients globally.However,the existing EHR systems mostly lack in providing appropriate security,entrusted access control and handling privacy and secrecy issues and challenges in current hospital infrastructures.Objective:To solve this delicate problem,we propose a Blockchain-enabled Hyperledger Fabric Architecture for different EHR systems.Methodology:In our EHR blockchain system,Peer nodes from various organizations(stakeholders)create a ledger network,where channels are created to enable secure and private communication between different stakeholders on the ledger network.Individual patients and other stakeholders are identified and registered on the network by unique digital certificates issued by membership service provider(MSP)component of the fabric architecture.Results:We created and implemented different Chaincodes to handle the business logic for executing separate EHR transactions on the network.The proposed fabric architecture provides a secure,transparent and immutable mechanism to store,share and exchange EHRs in a peer-to-peer network of different healthcare stakeholders.It ensures interoperability,scalability and availability in adapting the existing EHRs for strengthening and providing an effective and secure method to integrate and manage patient records among medical institutions in the healthcare ecosystem.