103 research outputs found
The Cloud Services Innovation Platform-Enabling Service-Based Environmental Modelling Using Infrastructure-As-A-Service Cloud Computing
Service oriented architectures allow modelling engines to be hosted over the Internet abstracting physical hardware configuration and software deployments from model users. Many existing environmental models are deployed as desktop applications running on user\u27s personal computers (PCs). Migration to service - based modelling centralizes the modelling functions to service hosts on the Internet . Users no longer require high-end PCs to run models and model updates encapsulating science advances can be disseminated more rapidly by hosting the modelling functions centrally via an Internet host instead of requiring software updates to user\u27s PCs . In this paper we present the Cloud Services Innovation Platform (CSIP), an Infrastructure -as -a -Service cloud application architecture , used to prototype development of distributed and scalable environmental modelling services. CSIP aims to provide modelling as a service to support both interactive (synchronous) and batch (asynchronous) modelling. CSIP enables c loud-based computing resources to be harnessed for both new and existing environmental models supporting the disaggregation of work into subtasks which execute in parallel using a scalable number of virtual machines. This paper presents CSIP \u27s implementation using the RUSLE2 model as a prototype model. RUSLE2 model service benchmarks are presented to demonstrate performance gains from using cloud resources. We also provide benchmarks for virtualization overhead observed using popular virtual machine hypervisors and demonstrate how application profile characteristics significantly impact performance when virtualized
Practical Fine-grained Privilege Separation in Multithreaded Applications
An inherent security limitation with the classic multithreaded programming
model is that all the threads share the same address space and, therefore, are
implicitly assumed to be mutually trusted. This assumption, however, does not
take into consideration of many modern multithreaded applications that involve
multiple principals which do not fully trust each other. It remains challenging
to retrofit the classic multithreaded programming model so that the security
and privilege separation in multi-principal applications can be resolved.
This paper proposes ARBITER, a run-time system and a set of security
primitives, aimed at fine-grained and data-centric privilege separation in
multithreaded applications. While enforcing effective isolation among
principals, ARBITER still allows flexible sharing and communication between
threads so that the multithreaded programming paradigm can be preserved. To
realize controlled sharing in a fine-grained manner, we created a novel
abstraction named ARBITER Secure Memory Segment (ASMS) and corresponding OS
support. Programmers express security policies by labeling data and principals
via ARBITER's API following a unified model. We ported a widely-used, in-memory
database application (memcached) to ARBITER system, changing only around 100
LOC. Experiments indicate that only an average runtime overhead of 5.6% is
induced to this security enhanced version of application
Not-a-Bot (NAB): Improving Service Availability in the Face of Botnet Attacks
A large fraction of email spam, distributed denial-of-service (DDoS) attacks, and click-fraud on web advertisements are caused by traffic sent from compromised machines that form botnets. This paper posits that by identifying human-generated traffic as such, one can service it with improved reliability or higher priority, mitigating the effects of botnet attacks.
The key challenge is to identify human-generated traffic in the absence of strong unique identities. We develop NAB (``Not-A-Bot''), a system to approximately identify and certify human-generated activity. NAB uses a small trusted software component called an attester, which runs on the client machine with an untrusted OS and applications. The attester tags each request with an attestation if the request is made within a small amount of time of legitimate keyboard or mouse activity. The remote entity serving the request sends the request and attestation to a verifier, which checks the attestation and implements an application-specific policy for attested requests.
Our implementation of the attester is within the Xen hypervisor. By analyzing traces of keyboard and mouse activity from 328 users at Intel, together with adversarial traces of spam, DDoS, and click-fraud activity, we estimate that NAB reduces the amount of spam that currently passes through a tuned spam filter by more than 92%, while not flagging any legitimate email as spam. NAB delivers similar benefits to legitimate requests under DDoS and click-fraud attacks
myTrustedCloud: Trusted cloud infrastructure for security-critical computation and data managment
Copyright @ 2012 IEEECloud Computing provides an optimal infrastructure to utilise and share both computational and data resources whilst allowing a pay-per-use model, useful to cost-effectively manage hardware investment or to maximise its utilisation. Cloud Computing also offers transitory access to scalable amounts of computational resources, something that is particularly important due to the time and financial constraints of many user communities. The growing number of communities that are adopting large public cloud resources such as Amazon Web Services [1] or Microsoft Azure [2] proves the success and hence usefulness of the Cloud Computing paradigm. Nonetheless, the typical use cases for public clouds involve non-business critical applications, particularly where issues around security of utilization of applications or deposited data within shared public services are binding requisites. In this paper, a use case is presented illustrating how the integration of Trusted Computing technologies into an available cloud infrastructure - Eucalyptus - allows the security-critical energy industry to exploit the flexibility and potential economical benefits of the Cloud Computing paradigm for their business-critical applications
Virtualization based password protection against malware in untrusted operating systems
Ministry of Education, Singapore under its Academic Research Funding Tier
Insider threat : memory confidentiality and integrity in the cloud
PhD ThesisThe advantages of always available services, such as remote device backup or data storage,
have helped the widespread adoption of cloud computing. However, cloud computing services
challenge the traditional boundary between trusted inside and untrusted outside. A
consumer’s data and applications are no longer in premises, fundamentally changing the
scope of an insider threat.
This thesis looks at the security risks associated with an insider threat. Specifically, we
look into the critical challenge of assuring data confidentiality and integrity for the execution
of arbitrary software in a consumer’s virtual machine. The problem arises from having
multiple virtual machines sharing hardware resources in the same physical host, while an
administrator is granted elevated privileges over such host.
We used an empirical approach to collect evidence of the existence of this security problem
and implemented a prototype of a novel prevention mechanism for such a problem.
Finally, we propose a trustworthy cloud architecture which uses the security properties our
prevention mechanism guarantees as a building block.
To collect the evidence required to demonstrate how an insider threat can become a
security problem to a cloud computing infrastructure, we performed a set of attacks targeting
the three most commonly used virtualization software solutions. These attacks attempt to
compromise data confidentiality and integrity of cloud consumers’ data. The prototype to
evaluate our novel prevention mechanism was implemented in the Xen hypervisor and tested
against known attacks.
The prototype we implemented focuses on applying restrictions to the permissive memory
access model currently in use in the most relevant virtualization software solutions. We
envision the use of a mandatory memory access control model in the virtualization software.
This model enforces the principle of least privilege to memory access, which means
cloud administrators are assigned with only enough privileges to successfully perform their
administrative tasks.
Although the changes we suggest to the virtualization layer make it more restrictive, our
solution is versatile enough to port all the functionality available in current virtualization
viii
solutions. Therefore, our trustworthy cloud architecture guarantees data confidentiality and
integrity and achieves a more transparent trustworthy cloud ecosystem while preserving
functionality.
Our results show that a malicious insider can compromise security sensitive data in the
three most important commercial virtualization software solutions. These virtualization solutions
are publicly available and the number of cloud servers using these solutions accounts
for the majority of the virtualization market. The prevention mechanism prototype we designed
and implemented guarantees data confidentiality and integrity against such attacks
and reduces the trusted computing base of the virtualization layer. These results indicate
how current virtualization solutions need to reconsider their view on insider threats
- …