Information flow control in cloud computing

Abstract-Cloud computing is an emerging computing paradigm where computing resources are provided as services over Internet while residing in a large data center. Even though it enables us to dynamically provide servers with the ability to address a wide range of needs, this paradigm brings forth many new challenges for the data security and access control as users outsource their sensitive data to clouds, which are beyond the same trusted domain as data owners. A fundamental problem is the existence of insecure information flows due to the fact that a service provider can access multiple virtual machines in clouds. Sensitive information may be leaked to unauthorized customers and such critical information flows could raise conflict-of-interest issues in cloud computing. In this paper, we propose an approach to enforce the infor mation flow policies at Infrastructure-as-a-Service (IaaS) layer in a cloud computing environment. Especially, we adopt Chinese Wall policies to address the problems of insecure information flow. We implement a proof-of-concept prototype system based on Eucalyptus open source packages to show the feasibility of our approach. This system facilitates the cloud management modules to resolve the conflict-of-interest issues for service providers in clouds. I

Enforcing Multi-user Security Policies in Cloud Computing

The user can access data from any server with unlimited data with the security. Multi-user tendency will cost lesser than the expected cost in the single user environment. While dealing with cloud computing, confidential data can be secured from the unauthorized access and internal threats. Cloud servers use smart techniques for achieving this requirement like encryption and decryption of data. The database is stored in the encrypted format on the server & a complex query can be fired on it. Cloud server will maintain the access control policies to reveal the data from the database that are in the encrypted format. In the access control policies, we use KMA (Key Management Authority) which provides the keyset for encryption & decryption of the database. The attributes entered by the user will create one public key which is cipher text based. So this technique is called as cipher text based technique. This key is used for encryption. While registering, user will choose the policy and select the attributes on which security policy is based. Because of this it is called as cipher text policy attribute based encryption (CP-ABE). To achieve this complex encryption, we can use many algorithms like AES or DES encryption algorithms with CPABE algorithm. This scheme allows making SQL-like queries on encrypted database in multiuser environment while at the same time, the database owner assign different access rights to users that defines a specific policy for the database. The major use of this encryption is privacy, access control and data confidentiality and multi-user access control.DOI:http://dx.doi.org/10.11591/ijece.v3i4.306

A multi-dimension taxonomy of insider threats in cloud computing

Security is considered a significant deficiency in cloud computing, and insider threats problem exacerbate security concerns in the cloud. In addition to that, cloud computing is very complex by itself, because it encompasses numerous technologies and concepts. Apparently, overcoming these challenges requires substantial efforts from information security researchers to develop powerful mitigation solutions for this emerging problem. This entails developing a taxonomy of insider threats in cloud environments encompassing all potential abnormal activities in the cloud, and can be useful for conducting security assessment. This paper describes the first phase of an ongoing research to develop a framework for mitigating insider threats in cloud computing environments. Primarily, it presents a multidimensional taxonomy of insider threats in cloud computing, and demonstrates its viability. The taxonomy provides a fundamental understanding for this complicated problem by identifying five dimensions, it also supports security engineers in identifying hidden paths, thus determining proper countermeasures, and presents a guidance covers all bounders of insiders threats issue in clouds, hence it facilitates researchers’ endeavours in tackling this problem. For instance, according to the hierarchical taxonomy, clearly many significant issues exist in public cloud, while conventional insider mitigation solutions can be used in private clouds. Finally, the taxonomy assists in identifying future research directions in this emerging area

Multi-tenancy in cloud computing

As Cloud Computing becomes the trend of information technology computational model, the Cloud security is becoming a major issue in adopting the Cloud where security is considered one of the most critical concerns for the large customers of Cloud (i.e. governments and enterprises). Such valid concern is mainly driven by the Multi-Tenancy situation which refers to resource sharing in Cloud Computing and its associated risks where confidentiality and/or integrity could be violated. As a result, security concerns may harness the advancement of Cloud Computing in the market. So, in order to propose effective security solutions and strategies a good knowledge of the current Cloud implementations and practices, especially the public Clouds, must be understood by professionals. Such understanding is needed in order to recognize attack vectors and attack surfaces. In this paper we will propose an attack model based on a threat model designed to take advantage of Multi-Tenancy situation only. Before that, a clear understanding of Multi-Tenancy, its origin and its benefits will be demonstrated. Also, a novel way on how to approach Multi-Tenancy will be illustrated. Finally, we will try to sense any suspicious behavior that may indicate to a possible attack where we will try to recognize the proposed attack model empirically from Google trace logs. Google trace logs are a 29-day worth of data released by Google. The data set was utilized in reliability and power consumption studies, but not been utilized in any security study to the extent of our knowledge

CP-ABE Access Control Scheme for Sensitive Data Set Constraint with Hidden Access Policy and Constraint Policy

CP-ABE (Ciphertext-Policy Attribute-Based Encryption) with hidden access control policy enables data owners to share their encrypted data using cloud storage with authorized users while keeping the access control policies blinded. However, a mechanism to prevent users from achieving successive access to a data owner’s certain number of data objects, which present a conflict of interest or whose combination thereof is sensitive, has yet to be studied. In this paper, we analyze the underlying relations among these particular data objects, introduce the concept of the sensitive data set constraint, and propose a CP-ABE access control scheme with hidden attributes for the sensitive data set constraint. This scheme incorporates extensible, partially hidden constraint policy. In our scheme, due to the separation of duty principle, the duties of enforcing the access control policy and the constraint policy are divided into two independent entities to enhance security. The hidden constraint policy provides flexibility in that the data owner can partially change the sensitive data set constraint structure after the system has been set up

Securing open multi-agent systems governed by electronic institutions

One way to build large-scale autonomous systems is to develop an open multi-agent system using peer-to-peer architectures in which agents are not pre-engineered to work together and in which agents themselves determine the social norms that govern collective behaviour. The social norms and the agent interaction models can be described by Electronic Institutions such as those expressed in the Lightweight Coordination Calculus (LCC), a compact executable specification language based on logic programming and pi-calculus. Open multi-agent systems have experienced growing popularity in the multi-agent community and are expected to have many applications in the near future as large scale distributed systems become more widespread, e.g. in emergency response, electronic commerce and cloud computing. A major practical limitation to such systems is security, because the very openness of such systems opens the doors to adversaries for exploit existing vulnerabilities. This thesis addresses the security of open multi-agent systems governed by electronic institutions. First, the main forms of attack on open multi-agent systems are introduced and classified in the proposed attack taxonomy. Then, various security techniques from the literature are surveyed and analysed. These techniques are categorised as either prevention or detection approaches. Appropriate countermeasures to each class of attack are also suggested. A fundamental limitation of conventional security mechanisms (e.g. access control and encryption) is the inability to prevent information from being propagated. Focusing on information leakage in choreography systems using LCC, we then suggest two frameworks to detect insecure information flows: conceptual modeling of interaction models and language-based information flow analysis. A novel security-typed LCC language is proposed to address the latter approach. Both static (design-time) and dynamic (run-time) security type checking are employed to guarantee no information leakage can occur in annotated LCC interaction models. The proposed security type system is then formally evaluated by proving its properties. A limitation of both conceptual modeling and language-based frameworks is difficulty of formalising realistic policies using annotations. Finally, the proposed security-typed LCC is applied to a cloud computing configuration case study, in which virtual machine migration is managed. The secrecy of LCC interaction models for virtual machine management is analysed and information leaks are discussed

An access control model for a South African National Electronic Health Record System

Countries such as South Africa have attempted to leverage eHealth by digitising patients’ medical records with the ultimate goal of improving the delivery of healthcare. This involves the use of the Electronic Health Record (EHR) which is a longitudinal electronic record of a patient’s information. The EHR is comprised of all of the encounters that have been made at different health facilities. In the national context, the EHR is also known as a national EHR which enables the sharing of patient information between points of care. Despite this, the realisation of a national EHR system puts patients' EHRs at risk. This is because patients’ information, which was once only available at local health facilities in the form of paper-based records, can be accessed anywhere within the country as a national EHR. This results in security and privacy issues since patients’ EHRs are shared with an increasing number of parties who are geographically distributed. This study proposes an access control model that will address the security and privacy issues by providing the right level of secure access to authorised clinicians. The proposed model is based on a combination of Role-Based Access Control (RBAC) and Attribute-Based Access Control (ABAC). The study found that RBAC is the most common access control model that is used within the healthcare domain where users’ job functions are based on roles. While RBAC is not able to handle dynamic events such as emergencies, the proposed model’s use of ABAC addresses this limitation. The development of the proposed model followed the design science research paradigm and was informed by the results of the content analysis plus an expert review. The content analysis sample was retrieved by conducting a systematic literature review and the analysis of this sample resulted in 6743 tags. The proposed model was evaluated using an evaluation framework via an expert review