Kiranbir Kaur^{1, *}, Sandeep Sharma¹, Karanjeet Singh Kahlon²

CMC-Computers, Materials & Continua, Vol.65, No.2, pp. 1625-1647, 2020, DOI:10.32604/cmc.2020.011535 - 20 August 2020

Abstract Vendor lock-in can occur at any layer of the cloud stack-Infrastructure, Platform, and Software-as-a-service. This paper covers the vendor lock-in issue at Platform as a Service (PaaS) level where applications can be created, deployed, and managed without worrying about the underlying infrastructure. These applications and their persisted data on one PaaS provider are not easy to port to another provider. To overcome this issue, we propose a middleware to abstract and make the database services as cloud-agnostic. The middleware supports several SQL and NoSQL data stores that can be hosted and ported among disparate PaaS… More >

Muhammad Adnan Khan^{1, *}, Sagheer Abbas², Ayesha Atta^{2, 3}, Allah Ditta⁴, Hani Alquhayz⁵, Muhammad Farhan Khan⁶, Atta-ur-Rahman⁷, Rizwan Ali Naqvi⁸

CMC-Computers, Materials & Continua, Vol.65, No.1, pp. 139-151, 2020, DOI:10.32604/cmc.2020.011416 - 23 July 2020

Abstract The innovation in technologies related to health facilities today is increasingly helping to manage patients with different diseases. The most fatal of these is the issue of heart disease that cannot be detected from a naked eye, and attacks as soon as the human exceeds the allowed range of vital signs like pulse rate, body temperature, and blood pressure. The real challenge is to diagnose patients with more diagnostic accuracy and in a timely manner, followed by prescribing appropriate treatments and keeping prescription errors to a minimum. In developing countries, the domain of healthcare is… More >

Leqi Jiang^{1, 2}, Zhangjie Fu^{1, 2, *}

Journal of Cyber Security, Vol.2, No.1, pp. 49-61, 2020, DOI:10.32604/jcs.2020.09308

Abstract Genetic Algorithm (GA) has been widely used to solve various optimization problems. As the solving process of GA requires large storage and computing resources, it is well motivated to outsource the solving process of GA to the cloud server. However, the algorithm user would never want his data to be disclosed to cloud server. Thus, it is necessary for the user to encrypt the data before transmitting them to the server. But the user will encounter a new problem. The arithmetic operations we are familiar with cannot work directly in the ciphertext domain. In this More >

Lei Li¹, Chungen Xu^{1, *}, Xiaoling Yu¹, Bennian Dou¹, Cong Zuo²

Journal of Cyber Security, Vol.2, No.1, pp. 9-23, 2020, DOI:10.32604/jcs.2020.06313

Abstract Searchable encryption technology makes it convenient to search encrypted data with keywords for people. A data owner shared his data with other users on the cloud server. For security, it is necessary for him to build a fine-grained and flexible access control mechanism. The main idea of this paper is to let the owner classify his data and then authorizes others according to categories. The cloud server maintains a permission matrix, which will be used to verify whether a trapdoor is valid or not. In this way we can achieve access control and narrow the More >

Zhengtao Liu^{1, *}, Yun Yang¹, Wen Gu¹, Jinyue Xia²

CMC-Computers, Materials & Continua, Vol.64, No.2, pp. 1233-1245, 2020, DOI:10.32604/cmc.2020.010846 - 10 June 2020

Abstract Most cloud services are built with multi-tenancy which enables data and configuration segregation upon shared infrastructures. It offers tremendous advantages for enterprises and service providers. It is anticipated that this situation will evolve to foster cross-tenant collaboration supported by Authorization as a service. To realize access control in a multi-tenant cloud computing environment, this study proposes a multi-tenant cloud computing access control model based on the traditional usage access control model by building trust relations among tenants. The model consists of three submodels, which achieve trust relationships between tenants with different granularities and satisfy the More >

Hailin Chen¹, Gang Xu³, Yuling Chen², Xiubo Chen^{1, 2, *}, Yixian Yang^{1, 2}, Ruibin Fan⁴, Kaixiang Zhang⁴, Huizhong Li⁴

Journal of Quantum Computing, Vol.2, No.1, pp. 57-83, 2020, DOI:10.32604/jqc.2020.09291 - 28 May 2020

Abstract Most existing blockchain schemes are based on the design concept “openness and transparency” to realize data security, which usually require transaction data to be presented in the form of plaintext. However, it inevitably brings the issues with respect to data privacy and operating performance. In this paper, we proposed a novel blockchain scheme called Cipherchain, which can process and maintain transaction data in the form of ciphertext while the characteristics of immutability and auditability are guaranteed. Specifically in our scheme, transactions can be encrypted locally based on a searchable encryption scheme called multi-user public key More >

Jiangheng Kou¹, Mingxing He^{1, *}, Ling Xiong¹, Zihang Ge², Guangmin Xie¹

CMC-Computers, Materials & Continua, Vol.64, No.1, pp. 297-312, 2020, DOI:10.32604/cmc.2020.09758 - 20 May 2020

Abstract With the development of communication technologies, various mobile devices and different types of mobile services became available. The emergence of these services has brought great convenience to our lives. The multi-server architecture authentication protocols for mobile cloud computing were proposed to ensure the security and availability between mobile devices and mobile services. However, most of the protocols did not consider the case of hierarchical authentication. In the existing protocol, when a mobile user once registered at the registration center, he/she can successfully authenticate with all mobile service providers that are registered at the registration center, More >

Alireza Poordavoodi¹, Mohammad Reza Moazami Goudarzi^2,*, Hamid Haj Seyyed Javadi³, Amir Masoud Rahmani⁴, Mohammad Izadikhah⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 525-570, 2020, DOI:10.32604/cmes.2020.08854 - 01 May 2020

Abstract With the growing number of Web services on the internet, there is a challenge to select the best Web service which can offer more quality-of-service (QoS) values at the lowest price. Another challenge is the uncertainty of QoS values over time due to the unpredictable nature of the internet. In this paper, we modify the interval data envelopment analysis (DEA) models [Wang, Greatbanks and Yang (2005)] for QoS-aware Web service selection considering the uncertainty of QoS attributes in the presence of desirable and undesirable factors. We conduct a set of experiments using a synthesized dataset… More >

Changji Wang^{1, *}, Yuan Yuan²

CMC-Computers, Materials & Continua, Vol.63, No.2, pp. 1031-1041, 2020, DOI:10.32604/cmc.2020.06278 - 01 May 2020

Abstract Ciphertext-policy attribute-based encryption (CP-ABE) is a promising cryptographic solution to the problem for enforcing fine-grained access control over encrypted data in the cloud. However, when applying CP-ABE to data outsourcing scenarios, we have to address the challenging issue of policy updates because access control elements, such as users, attributes, and access rules may change frequently. In this paper, we propose a notion of access policy updatable ciphertext-policy attribute-based encryption (APU-CP-ABE) by combining the idea of ciphertext-policy attribute-based key encapsulation and symmetric proxy re-encryption. When an access policy update occurs, data owner is no longer required… More >

Zhengtao Liu^{1, *}, Yi Ying¹, Yaqin Peng¹, Jinyue Xia²

CMC-Computers, Materials & Continua, Vol.63, No.2, pp. 861-871, 2020, DOI:10.32604/cmc.2020.07142 - 01 May 2020

Abstract Multi-tenant collaboration brings the challenge to access control in cloud computing environment. Based on the multi-tenant role-based access control (MTRBAC) model, a Temporal MT-RBAC (TMT-RBAC) model for collaborative cloud services is proposed. It adds the time constraint between trusted tenants, including usable role time constraint based on both calendar and interval time. Analysis shows that the new model strengthens the presentation ability of MT-RBAC model, achieves the finergrained access control, reduces the management costs and enhances the security of multitenant collaboration in cloud computing environment. More >