Necessary detection efficiencies for secure quantum key distribution and bound randomness

In recent years, several hacking attacks have broken the security of quantum cryptography implementations by exploiting the presence of losses and the ability of the eavesdropper to tune detection efficiencies. We present a simple attack of this form that applies to any protocol in which the key is constructed from the results of untrusted measurements performed on particles coming from an insecure source or channel. Because of its generality, the attack applies to a large class of protocols, from standard prepare-and-measure to device-independent schemes. Our attack gives bounds on the critical detection efficiencies necessary for secure quantum distribution, which show that the implementation of most partly device independent solutions is, from the point of view of detection efficiency, almost as demanding as fully device-independent ones. We also show how our attack implies the existence of a form of bound randomness, namely non-local correlations in which a non-signalling eavesdropper can find out a posteriori the result of any implemented measurement.Comment: 5 pages. v2: new title, published versio

FAIL MODE AND EFFECTS ANALYSIS (FMEA) APPLIED TO BIOFOOT/IBV2001 ® EQUIPMENT ADAPTATION FOR LONG JUMP

Increasingly, techniques and instruments coming from different fields of science are being used in sports research. This study proposes the application of an engineering methodology, the FMEA, for the adaptation of a plantar pressure measurement device to its safe and reliable use in the long jump analysis. This project's aim is to analyse the possible failures of the measurement equipment when used for long jump study, propose and validate changes in the measure equipment and in the research protocol. The FMEA methodology allowed to identify and to give priority to ninety four possible failures and their effects. Sixty four of them were solved, the remaining were of very low importance. In any case, further improvements were envised to eliminate all those possible failures. A new plantar pressure measuring equipment and a modified study protocol were obtained as a result

Joint secure communication and sensing in 6G networks

Joint communication and sensing is expected to be one of the features introduced by the sixth-generation (6G) wireless systems. This will enable a huge variety of new applications, hence, it is important to find suitable approaches to secure the exchanged information. Conventional security mechanisms may not be able to meet the stringent delay, power, and complexity requirements which opens the challenge of finding new lightweight security solutions. A promising approach coming from the physical layer is the secret key generation (SKG) from channel fading. While SKG has been investigated for several decades, practical implementations of its full protocol are still scarce. The aim of this chapter is to evaluate the SKG rates in real-life setups under a set of different scenarios. We consider a typical radar waveform and present a full implementation of the SKG protocol. Each step is evaluated to demonstrate that generating keys from the physical layer can be a viable solution for future networks. However, we show that there is not a single solution that can be generalized for all cases, instead, parameters should be chosen according to the context

The International Response to Climate Change: An Agenda for Global Health

As the international community negotiates a successor to the Kyoto Protocol of the United Nations Framework Convention on Climate Change (UNFCCC), there is new reason to hope that meaningful action might be taken to prevent devastating climate change. Even the more ambitious mitigation targets currently under negotiation, however, will not be sufficient to avoid a profound effect on the public\u27s health in coming decades, with the world\u27s poorest, most vulnerable populations bearing the disproportionate burden. The influence of historic and current emissions will be so substantial that it is imperative to reduce global emissions while at the same time preparing for the effects. Recently, the UNFCCC has begun to turn its attention to adaptation—changes to human systems to ameliorate the consequences of climate change. This Commentary proposes a new agenda for mitigation as well as adaptation approaches that emphasize the considerable health effects of climate change, which include increasingly intense and more frequent natural disasters, potential increases in vector-, food-, and water-borne infectious disease, and exacerbation of cardiovascular and respiratory disease. The effects of climate change will be experienced in every region but will disproportionately burden the global poor, exacerbating global health disparities and challenging the international community to address the inevitable questions of global social justice. Three key recommendations are proposed: (1) focus mitigation targets on broader health impacts, rather than framing climate change as a coastal issue; (2) incorporate land-use and agricultural approaches to mitigation alongside measures in the energy and transportation sectors to take advantage of co-benefits for health; and (3) fully fund adaptation projects as a global priority with an emphasis on strengthening health systems

Does Global Climate Policy Promote Low-Carbon Cities? Lessons Learnt From The CDM

An increasing proportion of greenhouse gas emissions is produced in urban areas in industrializing and developing countries. Recent research shows that per capita emissions in cities like Bangkok, Cape Town or Shanghai have already reached the level of cities like London, New York or Toronto. Large parts of the building stock and service infrastructure in cities in rapidly developing countries is built in the coming decade or two. Decisions taken in this sector today may therefore lock in a high emissions path. Based upon a survey of projects under the Clean Development Mechanism (CDM) of the Kyoto Protocol, we find that only about 1% of CDM projects have been submitted by municipalities, mostly in the waste management sector. This low participation is probably due to a lack of technical know how to develop CDM projects and an absence of motivation due to the long project cycle and the limited “visibility” of the projects for the electorate. Projects in the buildings and transport sector are rare, mainly due to heavy methodological challenges. A case study of the city network ICLEI and its experience with cities’ participation in the CDM adds insights from the practitioner side. We conclude that CDM reforms may make it easier for municipalities to engage in the CDM, and that new forms of cooperation between municipalities and project developers, potentially facilitated by ICLEI, are required to help to realize the urban CDM potential.CDM, cities, energy, climate policy, mitigation, transport, waste, local authorities

Enhanced No-Go Theorem for Quantum Position Verification

Based on the instantaneous nonlocal quantum computation (INQC), Buhrman et al. proposed an excellent attack strategy to quantum position verification (QPV) protocols in 2011, and showed that, if the colluding adversaries are allowed to previously share unlimited entangled states, it is impossible to design an unconditionally secure QPV protocol in the previous model. Here, trying to overcome this no-go theorem, we find some assumptions in the INQC attack, which are implicit but essential for the success of this attack, and present three different QPV protocols where these assumptions are not satisfied. We show that for the general adversaries, who execute the attack operations at every common time slot or the time when they detect the arrival of the challenge signals from the verifiers, secure QPV is achievable. This implies practically secure QPV can be obtained even if the adversaries is allowed to share unlimited entanglement previously. Here by "practically" we mean that in a successful attack the adversaries need launch a new round of attack on the coming qubits with extremely high frequency so that none of the possible qubits, which may be sent at random time, will be missed. On the other side, using such Superdense INQC (SINQC) attack, the adversaries can still attack the proposed protocols successfully in theory. The particular attack strategies to our protocols are presented respectively. On this basis, we demonstrate the impossibility of secure QPV with looser assumptions, i.e. the enhanced no-go theorem for QPV.Comment: 19 pages, single column, 3 tables, 6 figure