8,309 research outputs found
An Authorization Model for Multi-Provider Queries
We present a novel approach for the specification and enforcement
of authorizations that enables controlled data
sharing for collaborative queries in the cloud. Data authorities
can establish authorizations regulating access to their
data distinguishing three visibility levels (no visibility, encrypted
visibility, and plaintext visibility). Authorizations
are enforced in the query execution by possibly restricting
operation assignments to other parties and by adjusting visibility
of data on-the-fly. Our approach enables users and
data authorities to fully enjoy the benefits and economic
savings of the competitive open cloud market, while maintaining
control over data
Hierarchical Role-Based Access Control with Homomorphic Encryption for Database as a Service
Database as a service provides services for accessing and managing customers
data which provides ease of access, and the cost is less for these services.
There is a possibility that the DBaaS service provider may not be trusted, and
data may be stored on untrusted server. The access control mechanism can
restrict users from unauthorized access, but in cloud environment access
control policies are more flexible. However, an attacker can gather sensitive
information for a malicious purpose by abusing the privileges as another user
and so database security is compromised. The other problems associated with the
DBaaS are to manage role hierarchy and secure session management for query
transaction in the database. In this paper, a role-based access control for the
multitenant database with role hierarchy is proposed. The query is granted with
least access privileges, and a session key is used for session management. The
proposed work protects data from privilege escalation and SQL injection. It
uses the partial homomorphic encryption (Paillier Encryption) for the
encrypting the sensitive data. If a query is to perform any operation on
sensitive data, then extra permissions are required for accessing sensitive
data. Data confidentiality and integrity are achieved using the role-based
access control with partial homomorphic encryption.Comment: 11 Pages,4 figures, Proceedings of International Conference on ICT
for Sustainable Developmen
E-infrastructures fostering multi-centre collaborative research into the intensive care management of patients with brain injury
Clinical research is becoming ever more collaborative with multi-centre trials now a common practice. With this in mind, never has it been more important to have secure access to data and, in so doing, tackle the challenges of inter-organisational data access and usage. This is especially the case for research conducted within the brain injury domain due to the complicated multi-trauma nature of the disease with its associated complex collation of time-series data of varying resolution and quality. It is now widely accepted that advances in treatment within this group of patients will only be delivered if the technical infrastructures underpinning the collection and validation of multi-centre research data for clinical trials is improved. In recognition of this need, IT-based multi-centre e-Infrastructures such as the Brain Monitoring with Information Technology group (BrainIT - www.brainit.org) and Cooperative Study on Brain Injury Depolarisations (COSBID - www.cosbid.de) have been formed. A serious impediment to the effective implementation of these networks is access to the know-how and experience needed to install, deploy and manage security-oriented middleware systems that provide secure access to distributed hospital based datasets and especially the linkage of these data sets across sites. The recently funded EU framework VII ICT project Advanced Arterial Hypotension Adverse Event prediction through a Novel Bayesian Neural Network (AVERT-IT) is focused upon tackling these challenges. This chapter describes the problems inherent to data collection within the brain injury medical domain, the current IT-based solutions designed to address these problems and how they perform in practice. We outline how the authors have collaborated towards developing Grid solutions to address the major technical issues. Towards this end we describe a prototype solution which ultimately formed the basis for the AVERT-IT project. We describe the design of the underlying Grid infrastructure for AVERT-IT and how it will be used to produce novel approaches to data collection, data validation and clinical trial design is also presented
An authorization policy management framework for dynamic medical data sharing
In this paper, we propose a novel feature reduction approach to group words hierarchically into clusters which can then be used as new features for document classification. Initially, each word constitutes a cluster. We calculate the mutual confidence between any two different words. The pair of clusters containing the two words with the highest mutual confidence are combined into a new cluster. This process of merging is iterated until all the mutual confidences between the un-processed pair of words are smaller than a predefined threshold or only one cluster exists. In this way, a hierarchy of word clusters is obtained. The user can decide the clusters, from a certain level, to be used as new features for document classification. Experimental results have shown that our method can perform better than other methods.<br /
ACMiner: Extraction and Analysis of Authorization Checks in Android's Middleware
Billions of users rely on the security of the Android platform to protect
phones, tablets, and many different types of consumer electronics. While
Android's permission model is well studied, the enforcement of the protection
policy has received relatively little attention. Much of this enforcement is
spread across system services, taking the form of hard-coded checks within
their implementations. In this paper, we propose Authorization Check Miner
(ACMiner), a framework for evaluating the correctness of Android's access
control enforcement through consistency analysis of authorization checks.
ACMiner combines program and text analysis techniques to generate a rich set of
authorization checks, mines the corresponding protection policy for each
service entry point, and uses association rule mining at a service granularity
to identify inconsistencies that may correspond to vulnerabilities. We used
ACMiner to study the AOSP version of Android 7.1.1 to identify 28
vulnerabilities relating to missing authorization checks. In doing so, we
demonstrate ACMiner's ability to help domain experts process thousands of
authorization checks scattered across millions of lines of code
Delivering Live Multimedia Streams to Mobile Hosts in a Wireless Internet with Multiple Content Aggregators
We consider the distribution of channels of live multimedia content (e.g., radio or TV broadcasts) via multiple content aggregators. In our work, an aggregator receives channels from content sources and redistributes them to a potentially large number of mobile hosts. Each aggregator can offer a channel in various configurations to cater for different wireless links, mobile hosts, and user preferences. As a result, a mobile host can generally choose from different configurations of the same channel offered by multiple alternative aggregators, which may be available through different interfaces (e.g., in a hotspot). A mobile host may need to handoff to another aggregator once it receives a channel. To prevent service disruption, a mobile host may for instance need to handoff to another aggregator when it leaves the subnets that make up its current aggregator�s service area (e.g., a hotspot or a cellular network).\ud
In this paper, we present the design of a system that enables (multi-homed) mobile hosts to seamlessly handoff from one aggregator to another so that they can continue to receive a channel wherever they go. We concentrate on handoffs between aggregators as a result of a mobile host crossing a subnet boundary. As part of the system, we discuss a lightweight application-level protocol that enables mobile hosts to select the aggregator that provides the �best� configuration of a channel. The protocol comes into play when a mobile host begins to receive a channel and when it crosses a subnet boundary while receiving the channel. We show how our protocol can be implemented using the standard IETF session control and description protocols SIP and SDP. The implementation combines SIP and SDP�s offer-answer model in a novel way
- …