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… (More)
Attribute based messaging (ABM) enables message senders to dynamically create a list of recipients based on their attributes as inferred from an enterprise database. Such targeted messaging can reduce unnecessary communications and enhance privacy, but faces challenges in access control. In this paper, we explore an approach to ABM based on deriving access… (More)
<i>Attribute-Based Messaging</i> (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… (More)
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… (More)
The aim of this study was to prepare and characterize a self-emulsifying drug delivery system (SEDDS) with a high drug load of poorly water-soluble atorvastatin for the enhancement of dissolution and oral bioavailability. Solubility of atorvastatin in oil, surfactant, and cosurfactant was determined. Pseudo-ternary phase diagrams were constructed by the… (More)
Thesis: Mathematical modelling and optimization of biochemical systems: a method of analysis in biotechnology and biomedicine (Grade: 1.
We propose an tiered incentive system called <i>Integrity-Based Queuing (IBQ)</i> 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,… (More)
During an Internet distributed denial-of-service (DDoS) attack, attackers pose as a superpower overloading bandwidth and services that otherwise would have been lightly used by genuine users. These legitimate users send few packets and occasionally back-off and fail while competing for resources. The Internet architecture provides only modest support for… (More)