@article {18670,
	title = {Experiences with building an intrusion-tolerant group communication system},
	journal = {Software: Practice and Experience},
	volume = {38},
	year = {2008},
	month = {2008///},
	pages = {639 - 666},
	abstract = {There are many group communication systems (GCSs) that provide consistent group membership and reliable, ordered multicast properties in the presence of crash faults. However, relatively few GCS implementations are able to provide these properties in the presence of malicious faults resulting from intrusions. We describe the systematic transformation of a crash-tolerant GCS, namely C-Ensemble, into an intrusion-tolerant GCS, the ITUA GCS. To perform the transformation, we devised intrusion-tolerant versions of key group communication protocols. We then inserted implementations of the protocols into C-Ensemble and made significant changes to the rest of the C-Ensemble protocol stack to make the stack intrusion tolerant. We quantify the cost of providing intrusion-tolerant group communication in two ways. First, we quantify the implementation effort by presenting a detailed analysis of the amount of change required to the original C-Ensemble system. In doing so, we provide insight into the choice of building an intrusion-tolerant GCS from scratch versus building one by leveraging a crash-tolerant implementation. Second, we quantify the run-time performance cost of tolerating intrusions by presenting results from an experimental evaluation of the main intrusion-tolerant microprotocols. The results are analyzed to identify the parts that contribute the most overhead while providing intrusion tolerance during both normal operation and recovery from intrusions. Copyright {\textcopyright} 2007 John Wiley \& Sons, Ltd.},
	keywords = {distributed protocols, experimental evaluation, Fault tolerance, Group communication, intrusion tolerance},
	isbn = {1097-024X},
	doi = {10.1002/spe.848},
	url = {http://onlinelibrary.wiley.com/doi/10.1002/spe.848/abstract},
	author = {Ramasamy,HariGovind V. and Pandey,Prashant and Michel Cukier and Sanders,William H.}
}
@article {18653,
	title = {An architecture for adaptive intrusion-tolerant applications},
	journal = {Software: Practice and Experience},
	volume = {36},
	year = {2006},
	month = {2006///},
	pages = {1331 - 1354},
	abstract = {Applications that are part of a mission-critical information system need to maintain a usable level of key services through ongoing cyber-attacks. In addition to the well-publicized denial of service (DoS) attacks, these networked and distributed applications are increasingly threatened by sophisticated attacks that attempt to corrupt system components and violate service integrity. While various approaches have been explored to deal with DoS attacks, corruption-inducing attacks remain largely unaddressed. We have developed a collection of mechanisms based on redundancy, Byzantine fault tolerance, and adaptive middleware that help distributed, object-based applications tolerate corruption-inducing attacks. In this paper, we present the ITUA architecture, which integrates these mechanisms in a framework for auto-adaptive intrusion-tolerant systems, and we describe our experience in using the technology to defend a critical application that is part of a larger avionics system as an example. We also motivate the adaptive responses that are key to intrusion tolerance, and explain the use of the ITUA architecture to support them in an architectural framework. Copyright {\textcopyright} 2006 John Wiley \& Sons, Ltd.},
	keywords = {adaptive defense, adaptive middleware, Byzantine fault tolerance, intrusion tolerance, redundancy, survivability architecture},
	isbn = {1097-024X},
	doi = {10.1002/spe.747},
	url = {http://onlinelibrary.wiley.com/doi/10.1002/spe.747/abstract},
	author = {Pal,Partha and Rubel,Paul and Atighetchi,Michael and Webber,Franklin and Sanders,William H. and Seri,Mouna and Ramasamy,HariGovind and Lyons,James and Courtney,Tod and Agbaria,Adnan and Michel Cukier and Gossett,Jeanna and Keidar,Idit}
}
