• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.9
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• pp.3274-3297
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• 2021

Permission delegation is an important research issue in access control. It allows a user to delegate some of his permissions to others to reduce his workload, or enables others to complete some tasks on his behalf when he is unavailable to do so. As an ideal solution for controlling read access on outsourced data objects on the cloud, Ciphertext-Policy Attribute-Based Encryption (CP-ABE) has attracted much attention. Some existing CP-ABE schemes handle the read permission delegation through the delegation of the user's private key to others. Still, these schemes lack the further consideration of granularity and traceability of the permission delegation. To this end, this article proposes a flexible and fine-grained CP-ABE key delegation approach that supports white-box traceability. In this approach, the key delegator first examines the relations between the data objects, read permission thereof that he intends to delegate, and the attributes associated with the access policies of these data objects. Then he chooses a minimal attribute set from his attributes according to the principle of least privilege. He constructs the delegation key with the minimal attribute set. Thus, we can achieve the shortest delegation key and minimize the time of key delegation under the premise of guaranteeing the delegator's access control requirement. The Key Generation Center (KGC) then embeds the delegatee's identity into the key to trace the route of the delegation key. Our approach prevents the delegatee from combining his existing key with the new delegation key to access unauthorized data objects. Theoretical analysis and test results show that our approach helps the KGC transfer some of its burdensome key generation tasks to regular users (delegators) to accommodate more users.

• Journal of Internet Computing and Services
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• v.17 no.5
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• pp.9-16
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• 2016

Pervasive computing and Internet of Things (IoT) have recently received considerable interest to deploy solutions for the future Internet. Smart environments are integrated with Semantic Web to provide context-awareness to the processed information. Self-learning techniques have been adopted within smart solutions for efficient retrieval of data but do not process data with privacy parameters for in-place authorization. To overcome this issue, we present a novel approach of deploying access control as a service mechanism within Semantic Web based smart environment by using eXtensible Access Control Markup Language (XACML). The proposed XACML as a Service (XACMLaaS) approach offers fine-grained access control for protecting information within smart environment. In this paper, we have defined mathematical rules for each components of proposed access control service layer. These rules are for implementation of access control using XACML. The proposed approach allows the adaptation of authorization of information at component level and provides scalable solution for authorization policies and rule enforcement within smart environment.

• The KIPS Transactions:PartC
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• v.18C no.6
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• pp.369-378
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• 2011

To ensure data confidentiality and fine-grained access control in business environment, system model using KP-ABE(Key Policy-Attribute Based Encryption) and PRE(Proxy Re-Encryption) has been proposed recently. However, in previous study, data confidentiality has been effected by decryption right concentrated on cloud server. Also, Yu's work does not consider a access privilege management, so existing work become dangerous to collusion attack between malicious user and cloud server. To resolve this problem, we propose secure system model against collusion attack through dividing data file into header which is sent to privilege manager group and body which is sent to cloud server. And we construct the model of access privilege management using AONT based XOR threshold Secret Sharing, In addition, our scheme enable to grant weight for access privilege using XOR Share. In chapter 4, we differentiate existing scheme and proposed scheme.

• Journal of the Korea Society of Computer and Information
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• v.10 no.3 s.35
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• pp.119-132
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• 2005

The health care system revolutionized by the use of information and communication technologies. Computer information processing and electronic communication technologies play an increasingly important role in the area of health care. We propose a new role based access control model for pervasive health care systems, which changed location, time, environment information. Also our model can be solved the occurrence of an reduction authority problem to pervasive health care system at emergency environment. We propose a new role based access control model for pervasive health care systems, which combines role-to-role delegations, negative permission, context concept and dynamic context aware access control. With out approach we aim to preserver the advantages of RBAC and offer groat flexibility and fine-grained access control in pervasive healthcare information systems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.5
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• pp.2768-2780
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• 2019

Ciphertext-policy attribute-based encryption (CP-ABE) is one of the practical technologies to share data over cloud since it can protect data confidentiality and support fine-grained access control on the encrypted data. However, most of the previous schemes only focus on data confidentiality without considering data receiver privacy preserving. Recently, Li et al.(in TIIS, 10(7), 2016.7) proposed a CP-ABE with hidden access policy and testing, where they declare their scheme achieves privacy preserving for the encryptor and decryptor, and also has high decryption efficiency. Unfortunately, in this paper, we show that their scheme fails to achieve hidden access policy at first. It means that any adversary can obtain access policy information by a simple decisional Diffie-Hellman test (DDH-test) attack. Then we give a method to overcome this shortcoming. Security and performance analyses show that the proposed scheme not only achieves the privacy protection for users, but also has higher efficiency than the original one.

• Journal of KIISE
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• v.43 no.8
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• pp.933-945
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• 2016

Sharing data by multiple users on the public storage, e.g., the cloud, is considered to be efficient because the cloud provides on-demand computing service at anytime and anywhere. Secure data sharing is achieved by fine-grained access control. Existing symmetric and public key encryption schemes are not suitable for secure data sharing because they support 1-to-1 relationship between a ciphertext and a secret key. Attribute based encryption supports fine-grained access control, however it incurs linearly increasing ciphertexts as the number of attributes increases. Additionally, the decryption process has high computational cost so that it is not applicable in case of resource-constrained environments. In this study, we propose an efficient attribute-based secure data sharing scheme with outsourceable decryption. The proposed scheme guarantees constant-size ciphertexts irrespective of the number of attributes. In case of static attributes, the computation cost to the user is reduced by delegating approximately 95.3% of decryption operations to the more powerful storage systems, whereas 72.3% of decryption operations are outsourced in terms of dynamic attributes.

• Journal of the Korea Society of Computer and Information
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• v.27 no.9
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• pp.131-138
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• 2022

In this paper, we propose an FA-RBAC (FA-RBAC) model based on flexible properties. This model is assigned attribute-role-centric, making it easy to manage objects, as efficient as access control, and as the network environment changes, it can provide flexible access control. In addition, fine-grained permissions and simple access control can be achieved while balancing the advantages and disadvantages of the RBAC and ABAC models, reducing the number of access control rules by combining static attribute-based roles and dynamic attribute-based rules, and verifying the validity and performance benefits of the proposed model through comparison analysis and simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.303-306
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• 2011

System solutions for access control to the user's personal when you want to authenticate to the system is used. The valid user is really just a part of authorized users, the suitability of a valid user has been authenticated are not sure whether the problem is the fact. For example, one developer in the Unix operating system can be valid, but do not have permission to access the system should be limited for. In this paper, a single account for multiple users to use the system operational issues to improve the fine-grained delegation of authority, the session audit, the administrator account's policy-based management, with full rights the administrator account of distribution management and auditing the system overall is the study of access control measures.

• 한국정보컨버전스학회:학술대회논문집
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• 2008.06a
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• pp.75-86
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• 2008

This paper presents the design, implementation, and evaluation of the RFID Guardian, the first-ever unified platform for RFID security and privacy administration. The RFID Guardian resembles an "RFID firewall", enabling individuals to monitor and control access to their RFID tags by combining a standard-issue RFID reader with unique RFID tag emulation capabilities. Our system provides a platform for coordinated usage of RFID security mechanisms, offering fine-grained control over RFID-based auditing, key management, access control, and authentication capabilities. We have prototyped the RFID Guardian using off-the-shelf components, and our experience has shown that active mobile devices are a valuable tool for managing the security of RFID tags in a variety of applications, including protecting low-cost tags that are unable to regulate their own usage.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.1
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• pp.323-342
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• 2021

Personal health records (PHRs) is an electronic medical system that enables patients to acquire, manage and share their health data. Nevertheless, data confidentiality and user privacy in PHRs have not been handled completely. As a fine-grained access control over health data, ciphertext-policy attribute-based encryption (CP-ABE) has an ability to guarantee data confidentiality. However, existing CP-ABE solutions for PHRs are facing some new challenges in access control, such as policy privacy disclosure and dynamic policy update. In terms of addressing these problems, we propose a privacy protection and dynamic share system (PPADS) based on CP-ABE for PHRs, which supports full policy hiding and flexible access control. In the system, attribute information of access policy is fully hidden by attribute bloom filter. Moreover, data user produces a transforming key for the PHRs Cloud to change access policy dynamically. Furthermore, relied on security analysis, PPADS is selectively secure under standard model. Finally, the performance comparisons and simulation results demonstrate that PPADS is suitable for PHRs.