HORNET: High-speed Onion Routing at the Network Layer

We present HORNET, a system that enables high-speed end-to-end anonymous channels by leveraging next generation network architectures. HORNET is designed as a low-latency onion routing system that operates at the network layer thus enabling a wide range of applications. Our system uses only symmetric cryptography for data forwarding yet requires no per-flow state on intermediate nodes. This design enables HORNET nodes to process anonymous traffic at over 93 Gb/s. HORNET can also scale as required, adding minimal processing overhead per additional anonymous channel. We discuss design and implementation details, as well as a performance and security evaluation.Comment: 14 pages, 5 figure

Competitive Market Behavior: Convergence and asymmetry in the experimental double auction

We conducted a large number of controlled continuous double auction experiments to reproduce and stress‐test the phenomenon of convergence to competitive equilibrium under private information with decentralized trading feedback. Our main finding is that across a total of 104 markets (involving over 1,700 subjects), convergence occurs after a handful of trading periods. Initially, however, there is an inherent asymmetry that favors buyers, typically resulting in prices below equilibrium levels. Analysis of over 80,000 observations of individual bids and asks helps identify empirical ingredients contributing to the observed phenomena including higher levels of aggressiveness initially among buyers than sellers

Organic plant breeding and propagation: concepts and strategies

The organic farming system differs fundamentally from conventionally agriculture in the management of soil fertility,weeds,diseases and pests.Organic farmers depend greatly on conventionally bred and produced varieties,but require varieties better adapted to organic farming systems for further optimisation of organic agriculture.This includes a greater need for ‘reliable ’ varieties contributing to higher yield stability. In this thesis the concept of ‘naturalness ’ as applied in organic agriculture is elaborated and used as a guide to develop concepts and strategies for organic plant breeding and propagation.It refers to ecological and ethical principles,including the non-chemical and agro-ecological approach,and also taking the integrity of life into account. Based on these approaches the organic farming system is described and a general crop ideotype is defined.In the long run organic agriculture can only gain further progress when the genetic basis is renewed and broadened,and when the selection process is conducted under organic farming conditions. For self-fertilisers the concept of (isophenic)line mixture varieties seems most promising,being composed of lines which are phenotypically uniform but genetically heterogeneous.The ability to produce healthy seed under organic conditions should also be included in the variety ideotype.Further research is needed to develop protocols for seed health testing,to assess threshold values for seed-borne diseases and to design organic seed treatments. To improve transparency in the discussions on the ethical aspects of organic agriculture concerning the assessment of the suitability of the breeding and propagation techniques,the concept of the intrinsic value and integrity of plants has been elaborated and operationalised.Therefore principles are derived from the relevant characteristics of the nature of plants at four different levels:integrity of life,planttypic integrity,genotypic integrity and phenotypic integrity.Techniques at whole plant or crop level are most in line with these principles,respecting the self-reproductive ability and the reproductive barriers.The concept of integrity of plants can also give direction to the perception of plants in the selection process by the so-called breeder ’s eye. The consequences of the ecological and ethical principles for the concepts and strategies for organic plant breeding and propagation are demonstrated for the case of spring wheat in the Netherlands,including the adaptation and application of the protocol for Value for Cultivation and Use (VCU)testing.The participation of organic farmers with their experiential knowledge and farmer ’s eye was essential in the development of the spring wheat ideotype,but can also contribute to the selection process of new varieties. The proposed organic crop ideotype and variety concept may benefit not only organic farming systems,but in future also conventional systems moving away from high inputs of nutrients and chemical pesticides