HariGovind V. Ramasamy

Enhancing grid security using trusted virtualization

Grid applications increasingly have sophisticated functional and security requirements. Current techniques mostly protect the grid resource provider from attacks by the grid user, while leaving the user comparatively dependent on the well-behavior of the provider. We present the key components for a trustworthy grid architecture and address this trust asymmetry by using a combination of trusted computing and virtualization technologies. We propose a scalable offline attestation protocol, which allows the selection of trustworthy partners in the grid with low overhead. By providing multilateral security, i.e., security for both the grid user and the grid provider, our protocol increases the confidence that can be placed on the correctness of a grid computation and on the protection of user-provided assets.

Towards automated provisioning of secure virtualized networks

We describe a secure network virtualization framework that helps realize the abstraction of Trusted Virtual Domains (TVDs), a security-enhanced variant of virtualized network zones. The framework allows groups of related virtual machines running on separate physical machines to be connected together as though there were on their own separate network fabric and, at the same time, helps enforce cross-group security requirements such as isolation, confidentiality, security, and information flow control. The framework uses existing network virtualization technologies, such as Ethernet encapsulation, VLAN tagging, and VPNs, and combines and orchestrates them appropriately to implement TVDs. Our framework aims at automating the instantiation and deployment of the appropriate security mechanism and network virtualization technologies based on an input security model that specifies the required level of isolation and permitted network flows. We have implemented a prototype of the framework based on the Xen hypervisor. Experimental evaluation of the prototype shows that the performance of our virtual networking extensions is comparable to that of the standard Xen configuration.

Towards automated security policy enforcement in multi-tenant virtual data centers

Serdar Cabuk a, Chris I. Dalton a, Konrad Eriksson b, Dirk Kuhlmann a, HariGovind V. Ramasamy c, Gianluca Ramunno d, Ahmad-Reza Sadeghi e, Matthias Schunter b and Christian Stuble f a Hewlett–Packard Labs, Bristol, UK E-mails: serdar.cabuk@gmail.com, {cid,dirk.kuhlmann}@hp.com b IBM Zurich Research Laboratory, Ruschlikon, Switzerland E-mails: {kon,mts}@zurich.ibm.com c IBM T. J. Watson Research Center, Hawthorne, NY, USA E-mail: hvramasa@us.ibm.com d Politecnico di Torino, Turin, Italy E-mail: ramunno@polito.it e Ruhr-University Bochum, Germany E-mail: ahmad.sadeghi@trust.rub.de f Sirrix AG Security Technologies, Bochum, Germany E-mail: stueble@sirrix.com

Parsimonious asynchronous byzantine-fault-tolerant atomic broadcast

Atomic broadcast is a communication primitive that allows a group of n parties to deliver a common sequence of payload messages despite the failure of some parties. We address the problem of asynchronous atomic broadcast when up to t < n/3 parties may exhibit Byzantine behavior. We provide the first protocol with an amortized expected message complexity of

Dependability and Performance Evaluation of Intrusion-Tolerant Server Architectures

\mathcal{O}(n)

Application-storage discovery

per delivered payload. The most efficient previous solutions are the BFT protocol by Castro and Liskov and the KS protocol by Kursawe and Shoup, both of which have message complexity

Policy enforcement and compliance proofs for Xen virtual machines

\mathcal{O}(n^2)

An architecture for adaptive intrusion‐tolerant applications

. Like the BFT and KS protocols, our protocol is optimistic and uses inexpensive mechanisms during periods when no faults occur; when network instability or faults are detected, it switches to a more expensive recovery mode. The key idea of our solution is to replace reliable broadcast in the KS protocol by consistent broadcast, which reduces the message complexity from

Security-Aware Resource Allocation in Clouds

\mathcal{O}(n^2)

ITBVM: IT Business Value Modeler

to