Scalable and secure access control policy update for outsourced big data

The cipher-text policy attribute-based encryption is a promising technique to ensure the security in the third trust parties environment and offers opportunities to their users. However, the policy updating becomes a challenging issue when we use CP-ABE to construct access control schemes. The traditional method consists of presenting a huge work to the data owners, data retrieving, its re-encryption under the new access policy, and the re-sending back to the cloud. These interactions incur a heavy computation burden and a high communication on the data owner. In this paper, we propose a novel approach, in one hand, to enhance the security by using Blockchain technology, and in the other hand to update the access policy dynamically. We use Blockchain to deploy a policy in a manner that preserves security. We use also the cloud to store the data with CP-ABE, and especially, we focus on the delegation of the policy updating method to the cloud. This method can minimize the computation work and avoid the transmission of encrypted data by combining the ciphertext and previous access strategy. Moreover, we also design a policy updating algorithm. In our scheme, the security is occurred by two factors, the first one must satisfy the policy in the CP-ABE. The second one also must satisfy the policy deployed in the Blockchain to have the authorization token generated to access the desired resources.

Lattice-based Attribute-based encryption is a well-known cryptographic mechanism that can resist quantum attacks and has the ability of fine-grained access control, and it has a wide range of application scenarios in current Internet of Thing (IoT) era. However, lack of efficiency and existing the problem of large ciphertext expansion rate are the main disadvantages impede the applications of this mechanism. Thus, we propose an efficient and practical ciphertext policy attribute-based encryption (CP-ABE) scheme from lattices in the paper. In this scheme, to make the secret key reusable, we adjust access tree and propose a basic access tree structure, which can be converted from disjunctive normal form, and combine it with a light post-quantum scheme of Kyber. In addition, the compression method and plaintext expansion method are introduced to optimize the scheme. Our CP-ABE scheme is secure against chosen plaintext attack under the hardness of module learning with errors problem. We implement our scheme and compare it with three recent related schemes in terms of security, function and communication cost. Experiments and comparisons show that our CP-ABE scheme has advantages in high encryption efficiency, small matrix dimension, small key sizes, and low ciphertext expansion rate, which has some merit in practice.

How to control the access of the huge amount of big data becomes a very challenging issue, especially when big data are stored in the cloud. Ciphertext-policy attribute-based encryption (CP-ABE) is a promising encryption technique that enables end-users to encrypt their data under the access policies defined over some attributes of data consumers and only allows data consumers whose attributes satisfy the access policies to decrypt the data. In CP-ABE, the access policy is attached to the ciphertext in plaintext form, which may also leak some private information about end-users. Existing methods only partially hide the attribute values in the access policies, while the attribute names are still unprotected. In this paper, we propose an efficient and fine-grained big data access control scheme with privacy-preserving policy. Specifically, we hide the whole attribute (rather than only its values) in the access policies. To assist data decryption, we also design a novel attribute bloom filter to evaluate whether an attribute is in the access policy and locate the exact position in the access policy if it is in the access policy. Security analysis and performance evaluation show that our scheme can preserve the privacy from any linear secret-sharing schemes access policy without employing much overhead.

Cipher text-Policy Attribute Based Encryption (CP-ABE) is a promising cryptographic primitive for fine-grained access control of shared data. However, when CP-ABE is used to control outsourced data sharing, it confronts two obstacles. Firstly, the data owner must trust the attributes authority, secondly, the issue of attribute revocation of CP-ABE schemes, which suffers from such problems as different granularities of revocation, poor scalability and high computational complexity, is cumbersome. In this paper, we propose a new CP-ABE scheme that the data owners can fully control their outsourced shared data. We also resolve the issue of revocation including the entire user access privilege and just partial access right of the user, i.e., a subset of his/her attributes. Our proposed solution can achieve minimal overload by integrating CP-ABE with the access control of system. In addition, the data owners and the attributes authority can delegate most of laborious tasks to revocation proxy severs with the technique of proxy re-encryption. Finally, we present the quantitative test and analysis on the performance of our proposed scheme.

PurposeThe purpose of this paper Computing is a recent emerging cloud model that affords clients limitless facilities, lowers the rate of customer storing and computation and progresses the ease of use, leading to a surge in the number of enterprises and individuals storing data in the cloud. Cloud services are used by various organizations (education, medical and commercial) to store their data. In the health-care industry, for example, patient medical data is outsourced to a cloud server. Instead of relying onmedical service providers, clients can access theirmedical data over the cloud.Design/methodology/approachThis section explains the proposed cloud-based health-care system for secure data storage and access control called hash-based ciphertext policy attribute-based encryption with signature (hCP-ABES). It provides access control with finer granularity, security, authentication and user confidentiality of medical data. It enhances ciphertext-policy attribute-based encryption (CP-ABE) with hashing, encryption and signature. The proposed architecture includes protection mechanisms to guarantee that health-care and medical information can be securely exchanged between health systems via the cloud. Figure 2 depicts the proposed work's architectural design.FindingsFor health-care-related applications, safe contact with common documents hosted on a cloud server is becoming increasingly important. However, there are numerous constraints to designing an effective and safe data access method, including cloud server performance, a high number of data users and various security requirements. This work adds hashing and signature to the classic CP-ABE technique. It protects the confidentiality of health-care data while also allowing for fine-grained access control. According to an analysis of security needs, this work fulfills the privacy and integrity of health information using federated learning.Originality/valueThe Internet of Things (IoT) technology and smart diagnostic implants have enhanced health-care systems by allowing for remote access and screening of patients’ health issues at any time and from any location. Medical IoT devices monitor patients’ health status and combine this information into medical records, which are then transferred to the cloud and viewed by health providers for decision-making. However, when it comes to information transfer, the security and secrecy of electronic health records become a major concern. This work offers effective data storage and access control for a smart healthcare system to protect confidentiality. CP-ABE ensures data confidentiality and also allows control on data access at a finer level. Furthermore, it allows owners to set up a dynamic patients health data sharing policy under the cloud layer. hCP-ABES proposed fine-grained data access, security, authentication and user privacy of medical data. This paper enhances CP-ABE with hashing, encryption and signature. The proposed method has been evaluated, and the results signify that the proposed hCP-ABES is feasible compared to other access control schemes using federated learning.

With high flexibility and accessibility of data outsourcing environment such as cloud computing environment, several healthcare providers implement electronic personal health records (PHRs) to enable individual patients to manage their own health data in such resilient and scalable environment. However, PHRs contain highly sensitive information of which the security and privacy issues are the critical concern. Besides, PHRs owners should be capable to flexibly and securely define their own access policy for their outsourced data. In addition to the basic authentication feature, existing commercial cloud platforms usually provide symmetric or public key encryption as an optional feature to support data confidentiality for their tenants. However, such traditional encryption schemes are not suitable for data outsourcing environment because of high key management overhead of symmetric encryption and high maintenance cost for handling multiple copies of ciphertext for public key encryption solution. In this paper, we design and develop a secure and fine-grained access control scheme with lightweight access policy update for outsourced PHRs. Our proposed scheme is based on the ciphertext policy attribute-based encryption (CP-ABE) and proxy re-encryption (PRE). In addition, we introduce a policy versioning technique to support the full traceability of policy changes. Finally, we conducted the performance evaluation to demonstrate the efficiency of the proposed scheme.

An adaptive access control scheme based on trust degrees for edge computing

For enterprise systems running on public clouds in which the servers are outside the control domain of the enterprise, access control that was traditionally executed by reference monitors deployed on the system servers can no longer be trusted. Hence, a self-contained security scheme is regarded as an effective way for protecting outsourced data. However, building such a scheme that can implement the access control policy of the enterprise has become an important challenge. In this paper, we propose a self-contained data protection mechanism called RBAC-CPABE by integrating role-based access control (RBAC), which is widely employed in enterprise systems, with the ciphertext-policy attribute-based encryption (CP-ABE). First, we present a data-centric RBAC (DC-RBAC) model that supports the specification of fine-grained access policy for each data object to enhance RBAC’s access control capabilities. Then, we fuse DC-RBAC and CP-ABE by expressing DC-RBAC policies with the CP-ABE access tree and encrypt data using CP-ABE. Because CP-ABE enforces both access control and decryption, access authorization can be achieved by the data itself. A security analysis and experimental results indicate that RBAC-CPABE maintains the security and efficiency properties of the CP-ABE scheme on which it is based, but substantially improves the access control capability. Finally, we present an implemented framework for RBAC-CPABE to protect privacy and enforce access control for data stored in the cloud.

Attribute-based encryption (ABE) for cloud computing access control is reviewed in this article. A taxonomy and comprehensive assessment criteria of ABE are first proposed. In the taxonomy, ABE schemes are assorted into key-policy ABE (KP-ABE) schemes, ciphertext-policy ABE (CP-ABE) schemes, anti-quantum ABE schemes, and generic constructions. In accordance with cryptographically functional features, CP-ABE is further divided into nine subcategories with regard to basic functionality, revocation, accountability, policy hiding, policy updating, multi-authority, hierarchy, offline computation, and outsourced computation. In addition, a systematical methodology for discussing and comparing existing ABE schemes is proposed. For KP-ABE and each type of CP-ABE, the corresponding access control scenario is presented and explained by concrete examples. Specifically, the syntax of ABE is given followed by the adversarial model and security goals. ABE schemes are discussed according to the design strategies and special features and are compared in the light of the proposed assessment criteria with respect to security and performance. Compared to related state-of-the-art survey papers, this article not only provides a broader 12 categories of ABE schemes, but also makes a more comprehensive and holistic comparison. Finally, a number of open research challenges in ABE are pointed out.

When the Wireless Sensor Network (WSN) is combined with the Internet of Things (IoT), it can be employed in a wide range of applications, such as agriculture, industry 4.0, health care, smart homes, among others. Accessing the big data generated by these applications in Cloud Servers (CSs), requires higher levels of authenticity and confidentiality during communication conducted through the Internet. Signcryption is one of the most promising approaches nowadays for overcoming such obstacles, due to its combined nature, i.e., signature and encryption. A number of researchers have developed schemes to address issues related to access control in the IoT literature, however, the majority of these schemes are based on homogeneous nature. This will be neither adequate nor practical for heterogeneous IoT environments. In addition, these schemes are based on bilinear pairing and elliptic curve cryptography, which further requires additional processing time and more communication overheads that is inappropriate for real-time communication. Consequently, this paper aims to solve the above-discussed issues, we proposed an access control scheme for IoT environments using heterogeneous signcryption scheme with the efficiency and security hardiness of hyperelliptic curve. Besides the security services such as replay attack prevention, confidentiality, integrity, unforgeability, non-repudiations, and forward secrecy, the proposed scheme has very low computational and communication costs, when it is compared to existing schemes. This is primarily because of hyperelliptic curve lighter nature of key and other parameters. The AVISPA tool is used to simulate the security requirements of our proposed scheme and the results were under two backbends (Constraint Logic-based Attack Searcher (CL-b-AtSER) and On-the-Fly Model Checker (ON-t-FL-MCR)) proved to be SAFE when the presented scheme is coded in HLPSL language. This scheme was proven to be capable of preventing a variety of attacks, including confidentiality, integrity, unforgeability, non-repudiation, forward secrecy, and replay attacks.

In the cloud, for achieving access control and keeping data confidential, the data owners could adopt attribute-based encryption to encrypt the stored data. Users with limited computing power are however more likely to delegate the mask of the decryption task to the cloud servers to reduce the computing cost. As a result, attribute-based encryption with delegation emerges. Still, there are caveats and questions remaining in the previous relevant works. For instance, during the delegation, the cloud servers could tamper or replace the delegated ciphertext and respond a forged computing result with malicious intent. They may also cheat the eligible users by responding them that they are ineligible for the purpose of cost saving. Furthermore, during the encryption, the access policies may not be flexible enough as well. Since policy for general circuits enables to achieve the strongest form of access control, a construction for realizing circuit ciphertext-policy attribute-based hybrid encryption with verifiable delegation has been considered in our work. In such a system, combined with verifiable computation and encrypt-then-mac mechanism, the data confidentiality, the fine-grained access control and the correctness of the delegated computing results are well guaranteed at the same time. Besides, our scheme achieves security against chosen-plaintext attacks under the k-multilinear Decisional Diffie-Hellman assumption. Moreover, an extensive simulation campaign confirms the feasibility and efficiency of the proposed solution.

SummarySearchable encryption scheme‐based ciphertext‐policy attribute‐based encryption (CP‐ABE) is a effective scheme for providing multiuser to search over the encrypted data on cloud storage environment. However, most of the existing search schemes lack the privacy protection of the data owner and have higher computation time cost. In this paper, we propose a multiuser access control searchable privacy‐preserving scheme in cloud storage. First, the data owner only encrypts the data file and sets the access control list of multiuser and multiattribute for search data file. And the computing operation, which generates the attribute keys of the users' access control and the keyword index, is given trusted third party to perform for reducing the computation time of the data owner. Second, using CP‐ABE scheme, trusted third party embeds the users' access control attributes into their attribute keys. Only when those embedded attributes satisfy the access control list, the ciphertext can be decrypted accordingly. Finally, when the user searches data file, the keyword trap door is no longer generated by the user, and it is handed to the proxy server to finish. Also, the ciphertext is predecrypted by the proxy sever before the user performs decryption. In this way, the flaw of the client's limited computation resource can be solved. Security analysis results show that this scheme has the data privacy, the privacy of the search process, and the collusion‐resistance attack, and experimental results demonstrate that the proposed scheme can effectively reduce the computation time of the data owner and the users.

In this work, an oblivious transfer with complex access control scheme that is constructed based on ciphertext policy attribute based encryption (CP-ABE) scheme is proposed. In this scheme, the database server can enforce fine grained access control for each record where the authorized user is allowed to access, but the unauthorized user cannot, whereas it learns neither which record a user accesses, nor which attributes a user has. This scheme has the advantages as follows: First, it allows the expressive access control policies where access structures are based on linear secret sharing scheme that directly supports AND, OR and Threshold gates. Second, the communication complexity in this scheme is constant in the numbers of records which have been accessed. Third, this scheme is constructed in prime order bilinear group. Fourth, this scheme is secure in the standard model. To the best of our knowledge, this scheme is the first to obtain these features simultaneously.

Today a large volume of data is stored in cloud that requires fine grained accessibility for heterogeneous users. Cipher-text policy attribute based encryption (CP-ABE) has evolved into a promising solution for secure data storage with fine grained access control. In CP-ABE, the ciphertext is associated with an access policy (set of rules) and users can access the data if their attributes satisfies the access policy. However, existing CP-ABE schemes fail to perform in presence of large number of users and hierarchical relationships among them. Moreover, a majority of the CP-ABE schemes require large computational overhead for light weight applications. In this paper, we present a hierarchical attribute based cryptosystem by introducing hierarchical dependency between the users and thereby achieving multi-layer verification for fine grained data access. Moreover, our proposed cryptosystem is seamless to user revocation. The efficiency and security of our proposed cryptosystem have been analyzed and reported. Further we implement the proposed cryptosystem in Charm to demonstrate its practicality.

The information-centric Internet of things (IC-IoT) is different from the traditional Internet of things (IoT) in that the device-to-device pattern is generalized to a device-to-network pattern. Furthermore, in an IC-IoT environment, there is a demand for protecting the security of all data generated from IC-IoT devices. A cryptography scheme named attribute-based encryption (ABE) represents a smart method of providing the fine-grained access control that can sufficiently protect data security. The most attractive advantage of ABE is its expressive access policy, which makes the access control of data flexible and manageable. However, there is a serious problem caused by such an access policy; it incurs a greater ciphertext redundancy and computational overhead. This implies that the current ABE scheme is hard to implement in the thin client devices of IC-IoT. In this paper, we propose a universalized policy-compacting method via sharing public parts of the policy. Compared with the original policy, the compacted policy applies a more compact ciphertext and requires less computation, communication, and storage cost. However, the policy-compacting problem is proved to be a non-deterministic polynomial complete (NPC) problem. Thus, a greedy algorithm is provided to obtain an approximate minimum compacted policy scale. Finally, we propose a compact ciphertext-policy attribute-based encryption (CCP-ABE) scheme with the policy-compacting method. A security proof and performance evaluation show that the proposed CCP-ABE scheme provides a comprehensive performance improvement.