An Efficient Ciphertext Policy Attribute-Based Encryption Scheme from Lattices and Its Implementation

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.

Pairing-based CP-ABE with constant-size ciphertexts and secret keys for cloud environment

A Review on Data Privacy using Attribute-Based Encryption

Nowadays, many organizations are adopting cloud computing for storing the large amount of organization’s important and private data. Here, it becomes important to mange appropriate access rights to these data as it is stored outside the organization’s boundary and is handled by the third party service providers. The Ciphertext Policy Attribute-based Encryption (CPABE) scheme is the most widely utilized technique that offers encrypted access control. In the existing implementations of CPABE scheme, one of the significant issues that need to be addressed is an efficient revocation mechanism. In this paper a direct and immediate user revocation approach for CPABE scheme is presented. The proposed method offers direct user revocation by maintaining the revocation list and to keep revocation list smaller the validity time is embedded in the user’s secret key. The revoked users are still able to access the previously generated ciphertexts. Hence, ciphertext update process is incorporated and a separate immediate revocation list is maintained so that the revoked users’ access is restricted. Also, in the proposed system the revocation information is embedded in ciphertext as a separate part so the update process of ciphertext is more efficient.KeywordsAttributesRevocationABECPABERevocation listValidity periodCloudAccess structure

The cloud is the most suitable platform for storing and processing of data. Users are outsourcing data to the cloud to reduce the storage and maintenance cost locally. However, there are challenges to both cloud users as well as to the cloud service provider. The challenge for cloud service providers is to optimize the associated cost for the management and maintenance of uploaded data. The challenge for users is data privacy. To address these issues, encrypted data deduplication schemes proposed, but existing schemes suffer from security weakness and do not support data access control. In this paper, we propose an efficient ciphertext policy attribute-based encryption scheme for deduplication over encrypted data (ECP-ABE) in the cloud storage. Our scheme achieves privacy,deduplication along with access controls. The security and performance analysis demonstrates that our scheme is secure and efficient.

A lightweight key management scheme for key-escrow-free ECC-based CP-ABE for IoT healthcare systems

Attribute-based encryption schemes with constant-size ciphertexts

In a ciphertext-policy attribute-based encryption (CP-ABE) scheme, a user may have multiple attributes, and each attribute may be shared simultaneously by many users. The decryption key of an attribute can thus be shared by many users who all possess the attribute. For monetary gain, a malicious authorized user may reveal his/her decryption key to a third party, and it is difficult to trace the owner of primitive secret key from an exposed key. At the same time, this situation may also limit commercial applications of CP-ABE systems. To solve these problems and enable fine-grained access control for the encrypted data, we propose a traceable CP-ABE scheme with attribute-level user revocation for cloud storage (TUR-CPABE). Our scheme enjoys four advantages. First, it has the ability to trace malicious users who have leaked key information from the system. Second, it supports attribute-level user revocation for malicious users and allows ABE fine-grained access control. Third, it allows secret key updates and ciphertext updates to resist collusion attacks between users. Fourth, outsourcing encryption, decryption and attribute revocation are used to reduce the computational burden on data owners, data users and the trust authority, respectively. In addition, our scheme has been proven to be secure against chosen plaintext attacks under a selective access policy based on decisional q – BDHE assumption in the standard model.

In recent years, attribute-based encryption (ABE) provides a new idea to help researchers solving the problem of data privacy protection in cloud. But there are two issues in traditional ABE, the first issue is that the attributes in the access structures will be sent to users in cleartext together with the ciphertext. So a attacker has the opportunity to obtain some of the private information from the plaintext access structure. And the other issue is the traditional ABE scheme cannot revoke the users' illegal keys in an efficient way. To handle both of the above challenges, we come up with a large universe ciphertext-policy ABE (CP-ABE) scheme which supports partially hidden access structures (PHAS) and highly efficient key revocation at the same time in this paper. What's more, unlike most previous schemes, first our access structure is based on the expressive linear secret sharing scheme (LSSS) which supports both AND and OR gates in access formulas and second our scheme is built from the prime-order bilinear pairing groups. The comparison with other relevant works presents that our scheme is more comprehensive and efficient. Finally we rigorously prove and analyze that our scheme is selectively indistinguishable secure under chosen plaintext attacks (IND-CPA) in the random oracle model (ROM) and our access structure is really anonymous against off-line dictionary attacks.

The industrial Internet of Things (IIoT) generates a large amount of private data, which can be used to improve production efficiency and optimize production management decisions. However, the openness of the network and the limited resources of sensor devices pose security threats to industrial privacy data, such as illegal access and leakage. Attribute-based encryption (ABE) is a promising solution for solving the problem of private data sharing. Nevertheless, many time-consuming operations, such as bilinear pairing, security of access policies, and attribute revocation issues, pose challenges for ABE in practical applications. To address the above issues, we propose an efficient policy hiding ciphertext-policy ABE (CP-ABE) scheme based on a multivalued attribute access structure with wildcards. It introduces fog computing to achieve fully outsourced computation, reducing the computational overhead of resource constrained terminals. Meanwhile, attribute revocation and user revocation mechanisms were designed to achieve flexible and fine-grained access control. Based on the idea of reduction, we have demonstrated that our scheme is secure under the assumption of the decision q-bilinear Diffie-Hellman exponent. In addition, our scheme has both backward and forward securities. Finally, we compared and analyzed the proposed scheme with the existing schemes in terms of functionality and performance. Theoretical analysis and experimental simulation results show that our scheme has relatively complete functions and has certain advantages in communication costs and computational overhead.

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.

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.

Distributed key generation (DKG) is widely used in multi-party computation and decentralized applications. DKG has two phases, namely sharing and reconstruction. Most of the prior DKG protocols need at least 2 rounds for the sharing phase, in case some party raises a dispute. The existing 1-round DKG protocol [Fouque <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">et al.</i> , PKC’01], built based on a publicly verifiable secret sharing (PVSS) scheme, assumes a static adversary model and its reconstruction phase requires <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$O(n^{2})$ </tex-math></inline-formula> communication complexity. Motivated by the observation that a ciphertext-policy attribute-based encryption (CP-ABE) scheme hides secret sharing (SS) in ciphertext, we utilize decentralized CP-ABE to achieve the first adaptively secure 1-round DKG protocol. Firstly, a CP-ABE scheme enables the ciphertexts in DKG to be externally decrypted, making our protocol superior to the PVSS-based DKG protocol in reconstruction. The communication and computation complexities are both lowered to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$O(n)$ </tex-math></inline-formula> thanks to the constant-sized decryption key and the proposed batch decryption. The use of CP-ABE also makes our DKG protocol storage-friendly, i.e., the parties store no ciphertext after the sharing phase. Secondly, we add non-interactive zero-knowledge (NIZK) proofs to make the CP-ABE ciphertext publicly verifiable by leveraging the sigma protocol and the Fiat-Shamir heuristic. Thirdly, we demonstrate our protocol’s feasibility by presenting a proof-of-concept implementation over Ethereum, which is used as a public channel and a trustworthy computation platform. The implementation is a non-trivial task due to Ethereum’s incompatibility with the bilinear mapping group.

Designing lightweight security protocols for cloud-based Internet-of-Things (IoT) applications for battery-limited mobile devices, such as smart phones and laptops, is a topic of recent focus. Ciphertext-policy attribute-based encryption (CP-ABE) is a viable solution, particularly for cloud deployment, as an encryptor can “write” the access policy so that only authorized users can decrypt and have access to the data. However, most existing CP-ABE schemes are based on the costly bilinear maps, and require long decryption keys, ciphertexts and incur significant computation costs in the encryption and decryption (e.g. costs is at least linear to the number of attributes involved in the access policy). These design drawbacks prevent the deployment of CP-ABE schemes on battery-limited mobile devices. In this paper, we propose a new RSA-based CP-ABE scheme with constant size secret keys and ciphertexts (CSKC) and has $\mathcal {O}(1)$ time-complexity for each decryption and encryption. Our scheme is then shown to be secure against a chosen-ciphertext adversary, as well as been an efficient solution with the expressive AND gate access structures (in comparison to other related existing schemes). Thus, the proposed scheme is suitable for deployment on battery-limited mobile devices.

Ciphertext-policy attribute-based encryption (CP-ABE) has been widely adopted for securing the Internet of Things (IoT). However, traditional CP-ABE schemes still face several limitations in IoT data sharing. First, the plaintext access policy embedded in the ciphertext poses a risk of privacy leakage. Moreover, traditional CP-ABE schemes typically rely on a single secret sharing mechanism, which necessitates repeated transmissions to share large volumes of data. This leads to low efficiency in data sharing, making such schemes unsuitable for IoT environments. To address these issues, this paper proposes a policy-hidden CP-ABE access control scheme for the IoT that integrates a multi-secret sharing algorithm. The scheme employs multi-secret sharing techniques to enable secure and efficient data sharing, and adopts a hash-based encryption strategy to realize complete policy hiding. Simulation results demonstrate that the proposed scheme achieves strong security and performance, making it well-suited for resource-constrained IoT environments.