Peter L. Reiher

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Distributed denial-of-service (DDoS) is a rapidly growing problem. The multitude and variety of both the attacks and the defense approaches is overwhelming. This paper presents two taxonomies for classifying attacks and defenses, and thus provides researchers with a better understanding of the problem and the current solution space. The attack(More)
Distributed denial-of-service (DDoS) attacks present an Internet-wide threat. We propose D-WARD, a DDoS defense system deployed at source-end networks that autonomously detects and stops attacks originating from these networks. Attacks are detected by the constant monitoring of two-way traffic flows between the network and the rest of the Internet and(More)
Forcing all IP packets to carry correct source addresses can greatly help network security, attack tracing, and network problem debugging. However, due to asymmetries in today's Internet routing, routers do not have readily available information to verify the correctness of the source address for each incoming packet. In this paper we describe a new(More)
Reducing power consumption for server-class computers is important, since increased energy usage causes more heat dissipation, greater cooling requirements, reduced computational density, and higher operating costs. For a typical data center, storage accounts for 27% of energy consumption. Conventional server-class RAIDs cannot easily reduce power(More)
Ficus is a flexible replication facility with optimistic concurrency control designed to span a wide range of scales and network environments. Optimistic concurrency control provides rapid local access and high availability of files for update in the face of disconnection, at the cost of occasional conflicts that are only discovered when the system is(More)
Rumor is an optimistically replicated le system designed for use in mobile computers Rumor uses a peer model that allows oppor tunistic update propagation among any sites replicating les The paper outlines basic characteristics of replication systems for mobile computers describes the design and implementation of the Rumor le system and presents performance(More)
SUMMARY This research proposes and tests an approach to engineering distributed le systems that are aimed at wide-scale, Internet-based use. The premise is that replication is essential to deliver performance and availability, yet the traditional conservative replica consistency algorithms do not scale to this environment. Our Ficus replicated le system(More)
We describe a new approach to power saving and battery life extension on an untethered laptop through wireless remote processing of power-costly tasks. We ran a series of experiments comparing the power consumption of processes run locally with that of the same processes run remotely. We examined the trade-off between communication power expenditures and(More)
Defenses against flooding distributed denial-of-service (DDoS) commonly respond to the attack by dropping the excess traffic, thus reducing the overload at the victim. The major challenge is the differentiation of the legitimate from the attack traffic, so that the dropping policies can be selectively applied. We propose D-WARD, a source-end DDoS defense(More)
Recent research has demonstrated that portable computer users can save battery power by migrating tasks over wireless networks to server machines. Making this technique generally useful requires considerable automation. This paper describes a framework for automatically migrating tasks from a portable computer over a wireless network to a server and(More)