Peng Liu¹, Qian He^1,*, Baokang Zhao², Biao Guo¹, Zhongyi Zhai¹

CMC-Computers, Materials & Continua, Vol.76, No.3, pp. 3325-3343, 2023, DOI:10.32604/cmc.2023.041167

Abstract Cloud storage and edge computing are utilized to address the storage and computational challenges arising from the exponential data growth in IoT. However, data privacy is potentially risky when data is outsourced to cloud servers or edge services. While data encryption ensures data confidentiality, it can impede data sharing and retrieval. Attribute-based searchable encryption (ABSE) is proposed as an effective technique for enhancing data security and privacy. Nevertheless, ABSE has its limitations, such as single attribute authorization failure, privacy leakage during the search process, and high decryption overhead. This paper presents a novel approach called the blockchain-assisted efficient multi-authority attribute-based… More >

Lihong Guo^*, Jie Yang, Haitao Wu

CMC-Computers, Materials & Continua, Vol.76, No.2, pp. 1929-1946, 2023, DOI:10.32604/cmc.2023.039170

Abstract Attribute-based encryption (ABE) is a technique used to encrypt data, it has the flexibility of access control, high security, and resistance to collusion attacks, and especially it is used in cloud security protection. However, a large number of bilinear mappings are used in ABE, and the calculation of bilinear pairing is time-consuming. So there is the problem of low efficiency. On the other hand, the decryption key is not uniquely associated with personal identification information, if the decryption key is maliciously sold, ABE is unable to achieve accountability for the user. In practical applications, shared message requires hierarchical sharing in… More >

Zaid Abdulsalam Ibrahim^1,*, Muhammad Ilyas²

CMC-Computers, Materials & Continua, Vol.76, No.1, pp. 939-956, 2023, DOI:10.32604/cmc.2023.035798

Abstract Most research works nowadays deal with real-time Internet of Things (IoT) data. However, with exponential data volume increases, organizations need help storing such humongous amounts of IoT data in cloud storage systems. Moreover, such systems create security issues while efficiently using IoT and Cloud Computing technologies. Ciphertext-Policy Attribute-Based Encryption (CP-ABE) has the potential to make IoT data more secure and reliable in various cloud storage services. Cloud-assisted IoTs suffer from two privacy issues: access policies (public) and super polynomial decryption times (attributed mainly to complex access structures). We have developed a CP-ABE scheme in alignment with a Hidden Hierarchy Ciphertext-Policy… More >

Caihui Lan¹, Haifeng Li^2,3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.3, pp. 2985-3010, 2023, DOI:10.32604/cmes.2023.026321

Abstract Sharing of personal health records (PHR) in cloud computing is an essential functionality in the healthcare system. However, how to securely, efficiently and flexibly share PHRs data of the patient in a multi-receiver setting has not been well addressed. For instance, since the trust domain of the cloud server is not identical to the data owner or data user, the semi-trust cloud service provider may intentionally destroy or tamper shared PHRs data of user or only transform partial ciphertext of the shared PHRs or even return wrong computation results to save its storage and computation resource, to pursue maximum economic… More >

P. Prathap Nayudu, Krovi Raja Sekhar^*

Computer Systems Science and Engineering, Vol.46, No.1, pp. 1079-1092, 2023, DOI:10.32604/csse.2023.033961

Abstract The cloud allows clients to store and share data. Depending on the user’s needs, it is imperative to design an effective access control plan to share the information only with approved users. The user loses control of their data when the data is outsourced to the cloud. Therefore, access control mechanisms will become a significant challenging problem. The Ciphertext-Policy Attribute-Based Encryption (CP-ABE) is an essential solution in which the user can control data access. CP-ABE encrypts the data under a limited access policy after the user sets some access policies. The user can decrypt the data if they satisfy the… More >

Pooja Dhiman¹, Santosh Kumar Henge¹, Sartaj Singh¹, Avinash Kaur², Parminder Singh^2,3, Mustapha Hadabou^3,*

CMC-Computers, Materials & Continua, Vol.74, No.2, pp. 3297-3313, 2023, DOI:10.32604/cmc.2023.030558

Abstract This research paper puts emphasis on using cloud computing with Blockchain (BC) to improve the security and privacy in a cloud. The security of data is not guaranteed as there is always a risk of leakage of users’ data. Blockchain can be used in a multi-tenant cloud environment (MTCE) to improve the security of data, as it is a decentralized approach. Data is saved in unaltered form. Also, Blockchain is not owned by a single organization. The encryption process can be done using a Homomorphic encryption (HE) algorithm along with hashing technique, hereby allowing computations on encrypted data without the… More >

P. Prathap Nayudu, Krovi Raja Sekhar^*

Intelligent Automation & Soft Computing, Vol.35, No.3, pp. 3801-3813, 2023, DOI:10.32604/iasc.2023.032267

Abstract Due to the mobility of users in an organization, inclusion of dynamic attributes such as time and location becomes the major challenge in Ciphertext-Policy Attribute-Based Encryption (CP-ABE). By considering this challenge; we focus to present dynamic time and location information in CP-ABE with multi-authorization. At first, along with the set of attributes of the users, their corresponding location is also embedded. Geohash is used to encode the latitude and longitude of the user’s position. Then, decrypt time period and access time period of users are defined using the new time tree (NTT) structure. The NTT sets the encrypted duration of… More >

Qing Miao¹, Lan Guo¹, Yang Lu^1,*, Zhongqi Wang²

Intelligent Automation & Soft Computing, Vol.35, No.3, pp. 2737-2754, 2023, DOI:10.32604/iasc.2023.028693

Abstract Attribute-based encryption with keyword search (ABEKS) is a novel cryptographic paradigm that can be used to implement fine-grained access control and retrieve ciphertexts without disclosing the sensitive information. It is a perfect combination of attribute-based encryption (ABE) and public key encryption with keyword search (PEKS). Nevertheless, most of the existing ABEKS schemes have limited search capabilities and only support single or simple conjunctive keyword search. Due to the weak search capability and inaccurate search results, it is difficult to apply these schemes to practical applications. In this paper, an efficient expressive ABEKS (EABEKS) scheme supporting unbounded keyword universe over prime-order… More >

Zhen Yang¹, Hongao Zhang¹, Haiyang Yu^1,*, Zheng Li¹, Bocheng Zhu¹, Richard O. Sinnott²

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.1, pp. 269-282, 2021, DOI:10.32604/cmes.2021.015210

Abstract To address privacy concerns, data in the blockchain should be encrypted in advance to avoid data access from all users in the blockchain. However, encrypted data cannot be directly retrieved, which hinders data sharing in the blockchain. Several works have been proposed to deal with this problem. However, the data retrieval in these schemes requires the participation of data owners and lacks finer-grained access control. In this paper, we propose an attribute-based keyword search scheme over the encrypted blockchain, which allows users to search encrypted files over the blockchain based on their attributes. In addition, we build a file chain… More >

Muqadar Ali, Chungen Xu^*, Abid Hussain

Journal of New Media, Vol.2, No.1, pp. 31-43, 2020, DOI:10.32604/jnm.2020.09946

Abstract Attribute-based encryption is cryptographic techniques that provide flexible data access control to encrypted data content in cloud storage. Each trusted authority needs proper management and distribution of secret keys to the user’s to only authorized user’s attributes. However existing schemes cannot be applied multiple authority that supports only a single keywords search compare to multi keywords search high computational burden or inefficient attribute’s revocation. In this paper, a ciphertext policy attribute-based encryption (CP-ABE) scheme has been proposed which focuses on multi-keyword search and attribute revocation by new policy updating feathers under multiple authorities and central authority. The data owner encrypts… More >