We propose a public-key traitor tracing scheme in which (1) the size of a ciphertext is sublinear in the number of receivers and (2) black-box tracing is efficiently achieved against self-defensive pirate decoders. When assuming that a pirate decoder can take some self-defensive reaction (e.g., erasing all of the internal keys and shutting down) to escape from tracing if it detects tracing, it ...

We propose a tracing scheme of e-cash which has not only fair tracing ability but also lower computational complexity for comparisons. Many other protocols allow optimistic fair tracing which means that illegal tracing can be found after tracing and depositing in bank. But in this scheme, illegal tracing done by bank alone is impossible. We propose a marking mechanism based on a variant of an O...

Ray tracing in spherical Luneburg lenses has always been represented in 2D. All propagation planes in a 3D spherical Luneburg lens generate the same ray tracing, due to its radial symmetry. A geometry without radial symmetry generates a different ray tracing. For this reason, a new ray tracing method in 3D through spherical and elliptical Luneburg lenses using 2D methods is proposed. The physic...

The paper proposes process tracing as a research method to investigate IS development tasks. The fruitful application of process tracing is demonstrated using a study of data integration, an increasingly important part of system development. Second, the paper proposes new analysis techniques for analysing the process tracing data. Two analysis techniques that are new to IS process tracing resea...

BACKGROUND A large proportion of patients receiving antiretroviral therapy (ART) in low and middle income countries (LMICs) have unknown treatment outcomes and are classified as lost to follow-up (LTFU). Physical tracing of patients classified as LTFU is common; however, effects of tracing on outcomes remains unclear. The objective of this systematic review is to compare estimates of LTFU, mort...

Software requirements tracing is a systematic approach to keep track of development artifacts that need to be re-tested when requirements change. An important question is how much investment into tracing seems reasonable in an environment. This paper proposes an initial tracing activity model for trace generation and usage to help determine tracing efforts and support test managers in tailoring...

Packet tracing is a popular and efficient method for accelerating ray tracing. However, packet traversal techniques become inefficient when they are applied to path tracing since the secondary rays are incoherent. In this paper, we present a simple technique for improving the coherency of secondary rays. This technique uses the same sequence of random numbers for generating secondary rays for a...

Contact tracing is a well-established disease control measure that seeks to uncover cases by following chains of infection. This paper examines mathematical models of both single-step and iterative contact tracing schemes and analyses the ability of these procedures to trace core groups and the sensitivity of the intervention to the timescale of tracing. An iterative tracing process is shown to...

BACKGROUND Contact tracing plays an important role in the control of emerging infectious diseases, but little is known yet about its effectiveness. Here we deduce from a generic mathematical model how effectiveness of tracing relates to various aspects of time, such as the course of individual infectivity, the (variability in) time between infection and symptom-based detection, and delays in th...