Security of Patient health records (PHR) is the most important aspect of cryptography over the Internet due to its value and importance preferably in the medical Internet of Things (IoT). Search keywords access mechanism is one of the common approaches which is used to access PHR from database, but it is susceptible to various security vulnerabilities. Although Blockchain-enabled healthcare systems provide security, but it may lead to some loopholes in the existing schemes. However, these methods primarily focused on data storage, and blockchain is used as a database. In this paper, Blockchain as a distributed database is proposed with homomorphic encryption technique to ensure a secure search and keywords-based access to the database. Moreover, the proposed approach provides a secure key revocation mechanism and update various policies accordingly. A secure patient healthcare data access scheme is devised, which integrates blockchain and trust chain to fulfill the efficiency and security issues in the current schemes for sharing both types of digital healthcare data. Our proposed approach provides improved security, efficiency, and transparency with cost effectiveness. We performed our simulations based on the blockchain based tool termed as the Hyperledger fabric and Origionlab for analysis and evaluation. We have compared our proposed results with the benchmark models. Our comparative analysis justify that our proposed framework gives improvement in security and searchable mechanism for healthcare system.
Patient health record system (PHR) is the significant and vital information related to a patient history and his/her details. Digital healthcare system is considered as the platform for transferring and receiving patient health records. The existing digital healthcare systems rely on centralized servers which are more vulnerable to security breaches. The simplest solution is to integrate digital healthcare system to blockchain technology due to its wide application and security. More importantly blockchain provides peer-to-peer (P2P) and decentralized network system. In general, blockchain can be classified into three different categories, namely, private, public and consortium blockchain. It is a permissioned and consortium managed Blockchain, which means all peers are known to each other in the network. Moreover, it provides trust and security to all the parties involved. Hyper-ledger fabric is not domain specific, and it supports Java, Go, and Node.js for creating contracts and networks applications. There exist several searchable encryption (SE) methods to provide solution to the problems as mentioned above, but they are not as efficient regarding flexibility and anonymity [
Our proposed approach is more resilient to active collusion attack and key lost situations. Besides, our proposed method can be applied to different platforms, such as social media, fog computing and other Internet-of-Things (IoT) based applications. In this research paper we have proposed extended multi-users extended secure searchable encryption, which supports the participants to query securely against desired keyword search in the distributed ledger. The patient encrypts the data at the beginning and upload it to the blockchain. Our research method provides facility to the data owner once the data owner completes the encryption, and it will not be necessary to be involved another process until the patient needs policy revocation or deletion.
The rest of our paper is organized as follows. In Sections 1.1 and 1.2 we discuss the motivation of our proposed works and contributions. Section 2 provides literature review of the state-of-the-art schemes related to our proposed method. In Section 2.1, we discuss the Preliminaries Data, and Section 2.2 provides details of the Proposed Secure Search Algorithm. Moreover, in Section 2.3 Algorithm for Homomorphic Encryption is discussed. In Sections 2.4 and 2.5 the Proposed Access Control System Framework and the revocation policy for access control is illustrated. In Section 3, the experimental environment, parameters, and results are discussed. Finally, Section 4 concludes the paper and gives directions for future works.
Cloud computing is a distributed and flexible storage platform that can be accessed anytime and anywhere on demand. However, data outsourced to the Cloud can be considered insecure as the data owner has no control over data which potentially leads to more security threats. Similarly, security is the primary concern when dealing with medical records in the Cloud. Digital health record is one of the most valuable records potentially stored in the Cloud, which makes it more attractive for threat actors to find vulnerabilities and expose digital health records into high risks due to their value and price in the market. Regardless of currently advancement in access control models and frameworks, there still exist lots of issues. These issues include absence of measuring granularity in authorizing [
In our proposed framework, we will use Attribute Based Signature (ABS) because it offers unforgeability and anonymity of the signer [
Developing a novel lightweight consensus mechanism by combining with the BFT (Benzyntine Tolerance Protocol).
Measuring the trustworthiness of the user and prosumers before creating smart contracts and before initiating interactions among multi-parties.
It also helps in the accountability of the privacy and consent violation.
Moreover, it also helps to check the integrity before adding them to the genesis. Existing ABAC (Attribute Based Access Control) and RBAC (Role Based Access Control) system has low efficiency, and these are not machine intelligent [
To achieve more efficiency and security, we proposed an improved Access Control System with the combination of ABE, trust value and anonymity.
Our proposed approach will examine the parameters chosen, including user behavior, attributes, trust, unauthorized request, forbidden request, and range of specification. Users will be divided into different categories based upon the trust value such as very low, low, unknown, moderate, high, very, and high trusted users. A threshold value will be set if a user meets the threshold and satisfy the policy, then an access will be granted and vice versa.
The contribution of our proposed approach is summarized as following:
A detailed literature review of the state-of-art of patient and participants detection based on encryption and security algorithm.
A novel cross-domain and access control policies are proposed using homomorphic encryption.
We proposed the idea and implementation of policies revocation, updates, delete and add using homomorphic encryption.
We have achieved an optimum security and anonymous keyword search in the hyperledger fabric framework. Our proposed research method provide alternative private key in case of key is lost.
We have achieved the efficiency as compared to the existing method as this method exhibit more communication and encryption cost as these method needs to encrypt the data.
Our proposed methods provide more efficient solution to the users. In this section we have discussed the study and the loophole found in the previous research.
We have divided our literature review into two sections. First, we present a literature review of the current and previous methods used for PHR. The second part describes a review of access control model with their pros and cons.
Applications of blockchain in digital healthcare systems play an important role in healthcare industry. Self-generated data collection and verification processes in the correction and gathering of data from different sources, which are immutable, and tamper resistant against security breaches [
The performance measurement consists some of the parameters such as latency, throughput, and network security to achieve high throughput. In addition, in this research, we will prove the blockchain capability and importance in various aspects, which proves that it can be the subsequent technology for substituting current healthcare systems [
Chen et al. [
This section also describes the fundamental of the preliminary data, research findings and the importance of methodology.
Blockchain technology Uses of blockchain in digital healthcare systems which has an important role in the present digital health industry. Data distribution, redundancy and fault tolerance are such features which are supported by blockchain. Through this research, we have proposed a new access control method to achieve trust with secure access control using blockchain. Our proposed framework bypasses the dependencies on the CA and a SOP in the framework [
Where
We have designed a novel secure searchable algorithm that offer the facility to the users to encrypt at their own side and upload it to the distributed ledger. Through our proposed extended secure searchable algorithm, a user can anonymously search the keywords using blockchain users API. In case a user lost the key he or she can revoke the policy and can request for the new key. It provides protection against active collusion attacks. The list of parameters used in our proposed framework are listed in
S. No | Parameters | Details |
---|---|---|
1 | Blockchain network | |
2 | Clinician ID | |
3 | Lab ID | |
4 | Patient health record | |
5 | Ring signature | |
6 | Username | |
7 | Private key | |
8 | Integer | |
9 | Number of nodes | |
10 | Bi-linear order group | |
11 | Generator of addictive group 1 | |
12 | Generator of addictive group 2 | |
13 | Bi-linear identifier | |
14 | Homomorphic encryption | |
15 | Degree of signature |
Our proposed framework consists of four main participants’ i.e., Admin, doctor, patient, and Lab technician. We have proposed delegation policies and algorithms for each node.
We have designed a novel algorithm based on homomorphic encryption used for searching keywords in blockchain directory securely. The complete structure of this algorithm is described in algorithm 1.
We have proposed a novel secure access control system which is based on attribute based for our proposed framework.
The PHR access control system has four types of users, including admin, patients, clinicians, and laboratory staff. The precise execution of admin in a blockchain network is shown in Algorithm 1. The enrolment certificate of an admin is requested from the certification authority. The admin has full access to the system, including write, read, update, and removal of participants. Patient can revoke and update the policy against each PHR [
Due to the collusion attack our system will monitor the user behavior and interaction with the system. To remove the colluded node or user we have proposed the revocation policy. The shared key in the blockchain access control policies is revoked and new share key among the shareholder will be created. Update policy and proposed algorithm to implement the update policy we have proposed our novel algorithm called as update policy. In case of the data owner lost the private key so the update algorithm can be used to request for new private key.
However, to provide solution to the challenges and issues highlighted in the literature in multi-site clinical systems, we have proposed a blockchain-based access control and secure searchable encryption system for keyword searching, storing, retrieving, and sharing of personal healthcare data using homomorphic encryption. We model our system on Hyperledger Fabric and used homomorphic encryption for security and secure search. Our proposed algorithm is embedded in smart contracts for blockchain technology, and we have described all our novel algorithms function in detail. The parameters and the notations that contain in the blockchain are described in the tabular form as described in
In our proposed research Hyperledger caliper will be used as a tool for the blockchain network. It can support different hyperledger frameworks, e.g., fabric, composer, saw tooth, iroha, etc. We have implemented the homomorphic encryption for our encryption and decryption to provide secure searchable encryption mechanism. In this proposed research, caliper tool play an important role in the verification and execution of the system as well as various parameters. The parameters include latency, throughput, encryption and decryption time, computational cost. In our experimental setup the configuration parameters are modified as per assessment, such as block size, block time, endorsement policy, channel, keyword search, update policy, add policy, delete policy, and revoke policy. Our simulation setup configurations consist of the following specifications: Dataset size: 100 number of blocks + PHR Hardware: GPU Enabled System Software: Ethereum, Hyperledger Fabric Parameters: Block Height, Number of blockcs, No. Transac, No. PHR, Delay, signature creation, security (Execution time of Policies) and Cost (Execution Time of Blocks), Number of simulations : Number of Test performed on single data set. Number of rounds or transactions: 5000.
Experiment 1: We run our first experiment up-to 5000 rounds, and we evaluated our results based on the number of the personal health records sent
In
Number of people | FPR | FNR | FDR | ACC |
---|---|---|---|---|
100 | 0 | 0 | 0 | 1 |
200 | 0 | 0.022 | 0.025 | 0.96 |
300 | 0.002 | 0.029 | 0.035 | 0.87 |
The number of transactions sent per second. From the simulations we can see that our proposed framework is much better than the benchmark models. We have achieved more efficiency as compared to the benchmark models.
In
We did experiments on the policy revocation, policy creation and add policy. It can be easily seen that the authorization policy took less time as compared to the authentication policy and delegation policy. These simulations in
In
We have implemented a novel extended approach of homomorphic encryption in digital healthcare system leveraging blockchain technology which provides secure keyword search facility at the users end. Our research supports immutable, tamper resistant, and deliver secured data, which results in reduction of security breaches to the healthcare data. Furthermore, our novel mechanism allows blockchain users to encrypt data at their own premises and upload to the distributed ledger for record purpose. Users can securely search the desired health related data without decryption based on homomorphic SSE. Our technique provides resistance to active collusion and replay attacks due to the flexible policy revocation. In addition, Blockchain technology also supports distributed data, redundancy, and fault tolerance features for digital system. Hence, In this paper, current challenges and problems in the literature faced by the digital healthcare industry were solved. We proposed a framework and algorithm that enables access control policy for users to achieve privacy and security for patient health data in the PHR system. The proposed method provides more Independence to the users, and it support flexibility and fine-grained keyword search. We have justified our scheme and research algorithms as well aspolices through simulations on hyperledger fabric tool. We have used Pycharm tool for data analysis. With our proposed method, we have improved the security and anonymity as compared to the benchmark models such as Medrec, Medchain and Medbichain respectively.
Authors would like to thank for the support of Taif University Researchers Supporting Project number (TURSP-2020/98), Taif University, Taif, Saudi Arabia.