A Comprehensive Survey and Analysis on Access Control Schemes in Cloud Environment
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paper_title: Secure Computer Systems: Mathematical Foundations

paper_content:

This paper reports the first results of an investigation into solutions to problems of security in computer systems; it establishes the basis for rigorous investigation by providing a general descriptive model of a computer system.
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paper_title: Integrity Considerations for Secure Computer Systems

paper_content:

Abstract : An integrity policy defines formal access constraints which, if effectively enforced, protect data from improper modification. The author identifies the integrity problems posed by a secure military computer utility. Integrity policies addressing these problems are developed and their effectiveness evaluated. A prototype secure computer utility, Multics, is then used as a testbed for the application of the developed access controls.
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paper_title: Guidelines for Access Control System Evaluation Metrics

paper_content:

Nearly all applications include some form of access control (AC). AC is concerned with determining the allowed activities of legitimate users, mediating every attempt by a user to access a resource in the system. AC systems come with a wide variety of features and administrative capabilities, and their operational impact can be significant. In particular, this impact can pertain to administrative and user productivity, as well as to the organization’s ability to perform its mission. Therefore, it is reasonable to use quality metrics to verify the mechanical properties of AC systems. This document discusses the administration, enforcement, performance, and support properties of AC mechanisms that are embedded in each AC system. Because of the rigorous nature of the metrics and the knowledge needed to gather them, these metrics are intended to be used by AC experts who are evaluating the highest security AC systems.
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paper_title: A role-based access control model and reference implementation within a corporate intranet

paper_content:

This paper describes NIST's enhanced RBAC model and our approach to designing and implementing RBAC features for networked Web servers. The RBAC model formalized in this paper is based on the properties that were first described in Ferraiolo and Kuhn [1992] and Ferraiolo et al. [1995], with adjustments resulting from experience gained by prototype implementations, market analysis, and observations made by Jansen [1988] and Hoffman [1996]. The implementation of RBAC for the Web (RBAC/Web) provides an alternative to the conventional means of administering and enforcing authorization policy on a server-by-server basis. RBAC/Web provides administrators with a means of managing authorization data at the enterprise level, in a manner consistent with the current set of laws, regulations, and practices.
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paper_title: A Strong User Authentication Framework for Cloud Computing

paper_content:

Cloud computing is combination of various computing entities, globally separated, but electronically connected. As the geography of computation is moving towards corporate server rooms, it bring more issues including security, such as virtualization security, distributed computing, application security, identity management, access control and authentication. However, strong user authentication is the paramount requirement for cloud computing that restrict illegal access of cloud server. In this regard, this paper proposes a strong user authentication framework for cloud computing, where user legitimacy is strongly verified before enter into the cloud. The proposed framework provides identity management, mutual authentication, session key establishment between the users and the cloud server. A user can change his/her password, whenever demanded. Furthermore, security analysis realizes the feasibility of the proposed framework for cloud computing and achieves efficiency.
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paper_title: A unified attribute-based access control model covering DAC, MAC and RBAC

paper_content:

Recently, there has been considerable interest in attribute based access control (ABAC) to overcome the limitations of the dominant access control models (i.e, discretionary-DAC, mandatory-MAC and role based-RBAC) while unifying their advantages. Although some proposals for ABAC have been published, and even implemented and standardized, there is no consensus on precisely what is meant by ABAC or the required features of ABAC. There is no widely accepted ABAC model as there are for DAC, MAC and RBAC. This paper takes a step towards this end by constructing an ABAC model that has "just sufficient" features to be "easily and naturally" configured to do DAC, MAC and RBAC. For this purpose we understand DAC to mean owner-controlled access control lists, MAC to mean lattice-based access control with tranquility and RBAC to mean flat and hierarchical RBAC. Our central contribution is to take a first cut at establishing formal connections between the three successful classical models and desired ABAC models.
---
paper_title: Secure Computer Systems: Mathematical Foundations

paper_content:

This paper reports the first results of an investigation into solutions to problems of security in computer systems; it establishes the basis for rigorous investigation by providing a general descriptive model of a computer system.
---
paper_title: Addressing interoperability issues in access control models

paper_content:

Access control models need to be interoperable when administrative domains with heterogeneous access control models need to collaborate. Even, collaboration among homogeneous access control models is not straight-forward due to the different security orderings they might employ. In this paper, we briefly put forward an overlay formation mechanism based on chameleon hash functions. The mechanism allows collaborators to map their collaborating entities into a new collaboration specific security ordering that is agreeable to the peer collaborator. Collaborators use overlays as interoperation interfaces. By digitally signing each others' overlays, organizations enter into collaboration. Since overlays are virtual mappings, defining an overlay does not interfere with the access control model of the host organization. The use of overlays hides the internal security ordering of an organization from its collaborators. The trapdoor collision property of chameleon hash function ensures the privacy of collaboration agreements.
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paper_title: Guidelines for Access Control System Evaluation Metrics

paper_content:

Nearly all applications include some form of access control (AC). AC is concerned with determining the allowed activities of legitimate users, mediating every attempt by a user to access a resource in the system. AC systems come with a wide variety of features and administrative capabilities, and their operational impact can be significant. In particular, this impact can pertain to administrative and user productivity, as well as to the organization’s ability to perform its mission. Therefore, it is reasonable to use quality metrics to verify the mechanical properties of AC systems. This document discusses the administration, enforcement, performance, and support properties of AC mechanisms that are embedded in each AC system. Because of the rigorous nature of the metrics and the knowledge needed to gather them, these metrics are intended to be used by AC experts who are evaluating the highest security AC systems.
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paper_title: Requirements for scalable access control and security management architectures

paper_content:

Maximizing local autonomy by delegating functionality to end nodes when possible (the end-to-end design principle) has led to a scalable Internet. Scalability and the capacity for distributed control have unfortunately not extended well to resource access-control policies and mechanisms. Yet management of security is becoming an increasingly challenging problem in no small part due to scaling up of measures such as number of users, protocols, applications, network elements, topological constraints, and functionality expectations. In this article, we discuss scalability challenges for traditional access-control mechanisms at the architectural level and present a set of fundamental requirements for authorization services in large-scale networks. We show why existing mechanisms fail to meet these requirements and investigate the current design options for a scalable access-control architecture. We argue that the key design options to achieve scalability are the choice of the representation of access control policy, the distribution mechanism for policy, and the choice of the access-rights revocation scheme. Although these ideas have been considered in the past, current access-control systems in use continue to use simpler but restrictive architectural models. With this article, we hope to influence the design of future access-control systems towards more decentralized and scalable mechanisms.
---
paper_title: A role-based access control model and reference implementation within a corporate intranet

paper_content:

This paper describes NIST's enhanced RBAC model and our approach to designing and implementing RBAC features for networked Web servers. The RBAC model formalized in this paper is based on the properties that were first described in Ferraiolo and Kuhn [1992] and Ferraiolo et al. [1995], with adjustments resulting from experience gained by prototype implementations, market analysis, and observations made by Jansen [1988] and Hoffman [1996]. The implementation of RBAC for the Web (RBAC/Web) provides an alternative to the conventional means of administering and enforcing authorization policy on a server-by-server basis. RBAC/Web provides administrators with a means of managing authorization data at the enterprise level, in a manner consistent with the current set of laws, regulations, and practices.
---
paper_title: Guidelines for Access Control System Evaluation Metrics

paper_content:

Nearly all applications include some form of access control (AC). AC is concerned with determining the allowed activities of legitimate users, mediating every attempt by a user to access a resource in the system. AC systems come with a wide variety of features and administrative capabilities, and their operational impact can be significant. In particular, this impact can pertain to administrative and user productivity, as well as to the organization’s ability to perform its mission. Therefore, it is reasonable to use quality metrics to verify the mechanical properties of AC systems. This document discusses the administration, enforcement, performance, and support properties of AC mechanisms that are embedded in each AC system. Because of the rigorous nature of the metrics and the knowledge needed to gather them, these metrics are intended to be used by AC experts who are evaluating the highest security AC systems.
---
paper_title: Improving privacy and security in multi-authority attribute-based encryption

paper_content:

Attribute based encryption (ABE) [13] determines decryption ability based on a user's attributes. In a multi-authority ABE scheme, multiple attribute-authorities monitor different sets of attributes and issue corresponding decryption keys to users, and encryptors can require that a user obtain keys for appropriate attributes from each authority before decrypting a message. Chase [5] gave a multi-authority ABE scheme using the concepts of a trusted central authority (CA) and global identifiers (GID). However, the CA in that construction has the power to decrypt every ciphertext, which seems somehow contradictory to the original goal of distributing control over many potentially untrusted authorities. Moreover, in that construction, the use of a consistent GID allowed the authorities to combine their information to build a full profile with all of a user's attributes, which unnecessarily compromises the privacy of the user. In this paper, we propose a solution which removes the trusted central authority, and protects the users' privacy by preventing the authorities from pooling their information on particular users, thus making ABE more usable in practice.
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paper_title: Time-Based Proxy Re-encryption Scheme for Secure Data Sharing in a Cloud Environment

paper_content:

A fundamental approach for secure data sharing in a cloud environment is to let the data owner encrypt data before outsouring. To simultaneously achieve fine-grained access control on encrypted data and scalable user revocation, existing work combines attribute-based encryption (ABE) and proxy re-encryption (PRE) to delegate the cloud service provider (CSP) to execute re-encryption. However, the data owner should be online in order to send the PRE keys to the CSP in a timely fashion, to prevent the revoked user from accessing the future data. The delay of issuing the PRE keys may cause potential security risks. In this paper, we propose a time-based proxy re-encryption (TimePRE) scheme to allow a user's access right to expire automatically after a predetermined period of time. In this case, the data owner can be offline in the process of user revocations. The basic idea is to incorporate the concept of time into the combination of ABE and PRE. Specifically, each data is associated with an attribute-based access structure and an access time, and each user is identified by a set of attributes and a set of eligible time periods which denote the period of validity of the user's access right. Then, the data owner and the CSP are required to share a root secret key in advance, with which CSP can automatically update the access time of the data with the time that it receives a data access request. Therefore, given the re-encrypted ciphertext, only the users whose attributes satisfy the access structure and whose access rights are effective in the access time can recover corresponding data.
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paper_title: Semantic access control for cloud computing based on e-Healthcare

paper_content:

With the increased development of cloud computing, access control policies have become an important issue in the security filed of cloud computing. Semantic web is the extension of current Web which aims at automation, integration and reuse of data among different web applications such as clouding computing. However, Semantic web applications pose some new requirements for security mechanisms especially in the access control models. In this paper, we analyse existing access control methods and present a semantic based access control model which considers semantic relations among different entities in cloud computing environment. We have enriched the research for semantic web technology with role-based access control that is able to be applied in the field of medical information system or e-Healthcare system. This work demonstrates how the semantic web technology provides efficient solutions for the management of complex and distributed data in heterogeneous systems, and it can be used in the medical information systems as well.
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paper_title: The privacy-aware access control system using attribute-and role-based access control in private cloud

paper_content:

Cloud is a relatively new concept and so it is unsurprising that the information assurance, data protection, network security and privacy concerns have yet to be fully addressed. The cloud allows users to avoid upfront hardware and software investments, gain flexibility, collaborate with others, and take advantage of the sophisticated services. However, security is a huge issue for cloud users especially access control, user profile management and accessing services offered by the private cloud environment. A privacy enhancement system on Academic-based private cloud system using Eucalyptus open source cloud infrastructure has been proposed in this paper. This system provides the cloud users to improve the privacy and security of the private personal data. Two approaches (Role-based Access Control and Attribute-based Access Control model) are combined as a new approach (ARBAC). This means that they are applied to improve the privacy which supports both mandatory and discretionary access control needs on the target private cloud system.
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paper_title: Attribute-based encryption for fine-grained access control of encrypted data

paper_content:

As more sensitive data is shared and stored by third-party sites on the Internet, there will be a need to encrypt data stored at these sites. One drawback of encrypting data, is that it can be selectively shared only at a coarse-grained level (i.e., giving another party your private key). We develop a new cryptosystem for fine-grained sharing of encrypted data that we call Key-Policy Attribute-Based Encryption (KP-ABE). In our cryptosystem, ciphertexts are labeled with sets of attributes and private keys are associated with access structures that control which ciphertexts a user is able to decrypt. We demonstrate the applicability of our construction to sharing of audit-log information and broadcast encryption. Our construction supports delegation of private keys which subsumesHierarchical Identity-Based Encryption (HIBE).
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paper_title: Ensuring access control in cloud provisioned healthcare systems

paper_content:

An important issues in cloud provisioned multi-tenant healthcare systems is the access control, which focuses on the protection of information against unauthorized access. As different tenants including hospitals, clinics, insurance companies, and pharmacies access the system, sensitive information should be provided only to authorized users and tenants. In this paper, we analyze the requirements of access control for healthcare multi-tenant cloud systems and propose to adapt Task-Role Based Access Control with constraints such as least privilege, separation of duty, delegation of tasks, and spatial and temporal access.
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paper_title: HASBE: A Hierarchical Attribute-Based Solution for Flexible and Scalable Access Control in Cloud Computing

paper_content:

Cloud computing has emerged as one of the most influential paradigms in the IT industry in recent years. Since this new computing technology requires users to entrust their valuable data to cloud providers, there have been increasing security and privacy concerns on outsourced data. Several schemes employing attribute-based encryption (ABE) have been proposed for access control of outsourced data in cloud computing; however, most of them suffer from inflexibility in implementing complex access control policies. In order to realize scalable, flexible, and fine-grained access control of outsourced data in cloud computing, in this paper, we propose hierarchical attribute-set-based encryption (HASBE) by extending ciphertext-policy attribute-set-based encryption (ASBE) with a hierarchical structure of users. The proposed scheme not only achieves scalability due to its hierarchical structure, but also inherits flexibility and fine-grained access control in supporting compound attributes of ASBE. In addition, HASBE employs multiple value assignments for access expiration time to deal with user revocation more efficiently than existing schemes. We formally prove the security of HASBE based on security of the ciphertext-policy attribute-based encryption (CP-ABE) scheme by Bethencourt and analyze its performance and computational complexity. We implement our scheme and show that it is both efficient and flexible in dealing with access control for outsourced data in cloud computing with comprehensive experiments.
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paper_title: Shared Authority Based Privacy-Preserving Authentication Protocol in Cloud Computing

paper_content:

Cloud computing is an emerging data interactive paradigm to realize users' data remotely stored in an online cloud server. Cloud services provide great conveniences for the users to enjoy the on-demand cloud applications without considering the local infrastructure limitations. During the data accessing, different users may be in a collaborative relationship, and thus data sharing becomes significant to achieve productive benefits. The existing security solutions mainly focus on the authentication to realize that a user's privative data cannot be illegally accessed, but neglect a subtle privacy issue during a user challenging the cloud server to request other users for data sharing. The challenged access request itself may reveal the user's privacy no matter whether or not it can obtain the data access permissions. In this paper, we propose a shared authority based privacy-preserving authentication protocol (SAPA) to address above privacy issue for cloud storage. In the SAPA, 1) shared access authority is achieved by anonymous access request matching mechanism with security and privacy considerations (e.g., authentication, data anonymity, user privacy, and forward security); 2) attribute based access control is adopted to realize that the user can only access its own data fields; 3) proxy re-encryption is applied to provide data sharing among the multiple users. Meanwhile, universal composability (UC) model is established to prove that the SAPA theoretically has the design correctness. It indicates that the proposed protocol is attractive for multi-user collaborative cloud applications.
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paper_title: RBTBAC: Secure access and management of EHR data

paper_content:

Security and privacy are widely recognized as important and personalized requirements for access and management of Electric Health Record (EHR) data. Different patients may have different privacy and security policies for their EHR data in different context. In this paper we argue that EHR data needs to be managed with customizable access control in both spatial and temporal dimension. We present a role-based and time-bound access control model (RBTBAC) that provides more flexibility of both roles (spatial capability) and temporal capability to control the access of sensitive data from time dimension. Through algorithmic combination of role-based access control and time-bound key management, RBTBAC model has three salient features. First, we have developed a privacy-aware and dynamic key structure for role-based privacy aware access and management of EHR data, focusing on the consistency of access authorization (including data and time interval) with the activated role of user. In addition to role-based access, a path-invisible EHR structure is build for preserving privacy of patients. Second, we have employed a time tree method for generating time granule values, offering fine granularity of time-bound access authorization and control. Our experimental results show that tree-like time structure can improve the performance of the key management scheme significantly and RBTBAC model is more suitable than existing solutions for EHR data management since it offers high-efficiency and better security and privacy for patients.
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paper_title: Role-Based Access-Control Using Reference Ontology in Clouds

paper_content:

In cloud computing, security is an important issue due to the increasing scale of users. Current approaches to access control on clouds do not scale well to multi-tenancy requirements because they are mostly based on individual user IDs at different granularity levels. However, the number of users can be enormous and causes significant overhead in managing security. RBAC (Role-Based Access Control) is attractive because the number of roles is significantly less, and users can be classified according to their roles. This paper proposes a RBAC model using a role ontology for Multi-Tenancy Architecture (MTA) in clouds. The ontology is used to build up the role hierarchy for a specific domain. Ontology transformation operations algorithms are provided to compare the similarity of different ontology. The proposed framework can ease the design of security system in cloud and reduce the complexity of system design and implementation.
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paper_title: Privacy-Preserving Decentralized Key-Policy Attribute-Based Encryption

paper_content:

Decentralized attribute-based encryption (ABE) is a variant of multi-authority based ABE whereby any attribute authority (AA) can independently join and leave the system without collaborating with the existing AAs. In this paper, we propose a user collusion avoidance scheme which preserves the user's privacy when they interact with multiple authorities to obtain decryption credentials. The proposed scheme mitigates the well-known user collusion security vulnerability found in previous schemes. We show that our scheme relies on the standard complexity assumption (decisional bilienar Deffie-Hellman assumption). This is contrast to previous schemes which relies on non-standard assumption (q-decisional Diffie-Hellman inversion).
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paper_title: Secure distributed key generation for discrete-log based cryptosystems

paper_content:

Distributed key generation is a main component of threshold cryptosystems and distributed cryptographic computing in general. Solutions to the distributed generation of private keys for discrete-log based cryptosystems have been known for several years and used in a variety of protocols and in many research papers. However, these solutions fail to provide the full security required and claimed by these works. We show how an active attacker controlling a small number of parties can bias the values of the generated keys, thus violating basic correctness and secrecy requirements of a key generation protocol. In particular, our attacks point out to the places where the proofs of security fail. Based on these findings we designed a distributed key generation protocol which we present here together with a rigorous proof of security. Our solution, that achieves optimal resiliency, can be used as a drop-in replacement for key generation modules as well as other components of threshold or proactive discrete-log based cryptosystems.
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paper_title: An Efficient Role Based Access Control System for Cloud Computing

paper_content:

coRBAC is a specifically optimized RBAC system for cloud computing environment. It inherits the existing RBAC's role model and dRBAC's domain model, optimizes and improves the access control system for services which are hosted on the cloud computing platform. coRBAC greatly improves the certification process and user experience by reducing the unnecessary process of establishing secure connection and setting up multi-level cache, reduces the space complexity and time complexity of access control system.
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Title: A Comprehensive Survey and Analysis on Access Control Schemes in Cloud Environment

Section 1: Introduction
Description 1: This section introduces the basics of cloud computing, different delivery models, fundamental security concerns, and the necessity of robust access control mechanisms in the cloud.

Section 2: Access Control in Cloud
Description 2: This section provides an overview of traditional access control schemes and emphasizes the need for improved mechanisms specifically tailored for the cloud environment.

Section 3: Mandatory Access Control Model
Description 3: This section describes the Mandatory Access Control (MAC) model, its characteristics, merits, demerits, and its applicability in the cloud environment.

Section 4: Discretionary Access Control Model
Description 4: This section details the Discretionary Access Control (DAC) model, its features, benefits, drawbacks, and challenges when applied to the cloud.

Section 5: Role Based Access Control Model
Description 5: This section discusses the Role-Based Access Control (RBAC) model, its operational principles, advantages, limitations, and methods to enhance its suitability for cloud computing.

Section 6: Attribute Based Access Control Model
Description 6: This section elaborates on the Attribute Based Access Control (ABAC) model, its dependency on attributes for making access decisions, and its role in cloud security.

Section 7: Risk Based Access Control Model
Description 7: This section introduces the Risk-Based Access Control (RBAC) model, explaining its approach to handling varying risk levels and its limitations in the context of cloud environments.

Section 8: Basic Requirements for Access Control Schemes in Cloud
Description 8: This section identifies and analyzes the essential requirements any access control scheme must meet to be effective in a cloud computing environment.

Section 9: Current Proposed Solutions
Description 9: This section reviews various contemporary access control models and solutions proposed for cloud environments, highlighting their features, benefits, and limitations.

Section 10: Prospects of Future Research and Conclusions
Description 10: This section discusses the challenges, future research directions, and concludes with insights into developing enhanced access control models for cloud computing.