1,101 research outputs found
Anonymous credit cards and their collusion analysis
Communications networks are traditionally used to bring information together. They can also be used to keep information apart in order to protect personal privacy. A cryptographic protocol specifies a process by which some information is transferred among some users and hidden from others. We show how to implement anonymous credit cards using simple cryptographic protocols. We pose, and solve, a collusion problem which determines whether it is possible for a subset of users to discover information that is designed to be hidden from them during or after execution of the anonymous credit card protocol
Copyright protection for the electronic distribution of text documents
Each copy of a text document can be made different in a nearly invisible way by repositioning or modifying the appearance of different elements of text, i.e., lines, words, or characters. A unique copy can be registered with its recipient, so that subsequent unauthorized copies that are retrieved can be traced back to the original owner.
In this paper we describe and compare several mechanisms for marking documents and several other mechanisms for decoding the marks after documents have been subjected to common types of distortion. The marks are intended to protect documents of limited value that are owned by individuals who would rather possess a legal than an illegal copy if they can be distinguished. We will describe attacks that remove the marks and countermeasures to those attacks.
An architecture is described for distributing a large number of copies without burdening the publisher with creating and transmitting the unique documents. The architecture also allows the publisher to determine the identity of a recipient who has illegally redistributed the document, without compromising the privacy of individuals who are not operating illegally.
Two experimental systems are described. One was used to distribute an issue of the IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS, and the second was used to mark copies of company private memoranda
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N/ACustomer experience is one strategic option for organisations wishing to differentiate their service offering. Little research however has been conducted to explain how service design and management practices influence customer experience in non-hedonic contexts, settings in which the objectives for the design of the delivery system are not experiential. The objective of this research is to address this gap in academic knowledge.
The conceptual framework used as the basis of the empirical research demonstrates how four experience mechanism constructs, incorporated into the design of the delivery system, facilitate the customer’s involvement in the delivery of the service and influence how they perceive the experience that emerges as a result. To explore the relevance of the framework two case studies were conducted. Data was collected principally through interviews with employees working at various levels throughout the organisations hierarchy and with customers. Observations and secondary source material also provided additional evidence.
The thesis provides an original and distinct contribution to knowledge, through three main findings: Firstly, the research found evidence that the conceptual framework was relevant to the design of the delivery system and in customers’ perception of their experience. This challenges assumptions in existing literature that experience might not be a relevant design consideration in non-hedonic service contexts. Secondly, the findings provide a point of distinction between experiences in hedonic and non-hedonic contexts. Finally the study extends experience design theory demonstrating how in the contexts studied, the experience mechanisms act as antecedents for the experience a customer perceives.
Whilst conducting only two case studies limits the impact of the findings, the propositions formulated to explain the key themes identified, can be used as a vehicle through which future quantitative research can be carried out, therefore extending the generalisability of the study beyond the contexts studied.N/
Tunable light-matter interaction and the role of hyperbolicity in graphene-hBN system
Hexagonal boron nitride (hBN) is a natural hyperbolic material which can also
accommodate highly dispersive surface phonon-polariton modes. In this paper, we
examine theoretically the mid-infrared optical properties of graphene-hBN
heterostructures derived from their coupled plasmon-phonon modes. We found that
the graphene plasmon couples differently with the phonons of the two
Reststrahlen bands, owing to their different hyperbolicity. This also leads to
distinctively different interaction between an external quantum emitter and the
plasmon-phonon modes in the two bands, leading to substantial modification of
its spectrum. The coupling to graphene plasmons allows for additional gate
tunability in the Purcell factor, and narrow dips in its emission spectra
Chiral plasmon in gapped Dirac systems
We study the electromagnetic response and surface electromagnetic modes in a
generic gapped Dirac material under pumping with circularly polarized light.
The valley imbalance due to pumping leads to a net Berry curvature, giving rise
to a finite transverse conductivity. We discuss the appearance of nonreciprocal
chiral edge modes, their hybridization and waveguiding in a nanoribbon
geometry, and giant polarization rotation in nanoribbon arrays
Anonymous credit card transactions
Techniques for performing credit-card transactions without disclosing the subject matter of the transaction to the institution providing the credit card. The techniques include the use of a communications exchange so that information and funds may be transferred without the destination for the transfer knowing the source of the information or funds and the use of public key encryption so that each party to the transaction and the communications exchange can read only the information the party or the exchange needs for its role in the transaction. Also disclosed are techniques for authenticating a card holder by receiving personal information from the card holder, using the information to ask the card holder one or more questions, and using the answers to authenticate the card holder
Targeting Neuropeptides to Bone Fractures for Accelerated Healing
In patients over the age of 65 especially, bone fractures represent a significant disease burden. Non-invasive drug therapies are not available for bone fractures which represents a problem for this population. Vasoactive intestinal peptide (VIP) and Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP), two neuromodulator peptides in the glucagon superfamily, have demonstrated positive regulation of osteoblast proliferation and activity. Using acidic oligopeptides, we have developed ligands that target to and accumulate at fracture sites. These targeting ligands can be synthesized in sequence with bone anabolic peptides to minimize off target effects and increase potency at the fracture site to create safer and more efficacious therapeutic molecules. The conjugation of PACAP and VIP to acidic oligopeptide targeting ligands results in compounds that demonstrate significant improvements in regeneration of bone at fracture site in vivo in terms of strength and mineralization of fracture callus
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