No abstract

Abstract-Denial-of-service (DoS) attacks are considered within the province of a shared channel model in which attack rates may be large but are bounded and client request rates vary within fixed bounds. In this setting, it is shown that clients can adapt effectively to an attack by increasing their request rate based on timeout windows to estimate attack rates. The server will be able to process client requests with high probability while pruning out most of the attack by selective random sampling. The protocol introduced here, called Adaptive Selective Verification (ASV), is shown to use bandwidth efficiently and does not require any server state or assumptions about network congestion. The main results of the paper are a formulation of optimal performance and a proof that ASV is optimal.Index Terms-Bandwidth, distributed denial of service (DDoS), performance analysis, selective verification, shared channel model, theorem.

Abstract-We consider Denial of Service (DoS) attacks within the province of a shared channel model in which attack rates may be large but are bounded and client request rates vary within fixed bounds. In this setting it is shown that the clients can respond effectively to an attack by using bandwidth as a payment scheme and time-out windows to adaptively boost request rates. The server will be able to process client requests with high probability while pruning out most of the attack by selective random sampling. Our protocol, which we call Adaptive Selective Verification (ASV) is shown to be efficient in terms of bandwidth consumption using both a theoretical model and network simulations. It differs from previously-investigated adaptive mechanisms for bandwidth-based payment by requiring very limited state on the server.

Attribute-Based Messaging (ABM) enables messages to be addressed using attributes of recipients rather than an explicit list of recipients. Such messaging offers benefits of efficiency, exclusiveness, and intensionality, but faces challenges in access control and confidentiality. In this article we explore an approach to intraenterprise ABM based on providing access control and confidentiality using information from the same attribute database exploited by the addressing scheme. We show how to address three key challenges. First, we demonstrate a manageable access control system based on attributes. Second, we demonstrate use of attribute-based encryption to provide end-to-end confidentiality. Third, we show that such a system can be efficient enough to support ABM for mid-size enterprises. Our implementation can dispatch confidential ABM messages approved by XACML policy review for an enterprise of at least 60,000 users with only seconds of latency.

We propose an tiered incentive system called IntegrityBased Queuing (IBQ) for protection against Internet Distributed Denial-of-Service (DDoS) attacks. Our proposal can be implemented step-by-step where each integrity improvement brings a direct benefit to the autonomous system making it. IBQ proposes preferential queuing based on integrity: good, bad and middle. Since implementation can rarely be complete or network-wide we provide incremental benefit by prioritizing service for domains with better integrity. We have provided a basic analysis to relate performance to measurable integrity of the client. We have designed the architecture for authentication, queuing and defense. We have tested IBQ for applications with real-time requirements and show how performance improves with higher assurance.