On the Security of the Automatic Dependent Surveillance-Broadcast Protocol

Automatic dependent surveillance-broadcast (ADS-B) is the communications protocol currently being rolled out as part of next generation air transportation systems. As the heart of modern air traffic control, it will play an essential role in the protection of two billion passengers per year, besides being crucial to many other interest groups in aviation. The inherent lack of security measures in the ADS-B protocol has long been a topic in both the aviation circles and in the academic community. Due to recently published proof-of-concept attacks, the topic is becoming ever more pressing, especially with the deadline for mandatory implementation in most airspaces fast approaching. This survey first summarizes the attacks and problems that have been reported in relation to ADS-B security. Thereafter, it surveys both the theoretical and practical efforts which have been previously conducted concerning these issues, including possible countermeasures. In addition, the survey seeks to go beyond the current state of the art and gives a detailed assessment of security measures which have been developed more generally for related wireless networks such as sensor networks and vehicular ad hoc networks, including a taxonomy of all considered approaches.Comment: Survey, 22 Pages, 21 Figure

Assessment of bacterial endosymbiont diversity in Otiorhynchus spp. (Coleoptera: Curculionidae) larvae using a multitag 454 pyrosequencing approach

<p>Abstract</p> <p>Background</p> <p>Weevils of the genus <it>Otiorhynchus</it> are regarded as devastating pests in a wide variety of horticultural crops worldwide. So far, little is known on the presence of endosymbionts in <it>Otiorhynchus</it> spp.. Investigation of endosymbiosis in this genus may help to understand the evolution of different reproductive strategies in these weevils (parthenogenesis or sexual reproduction), host-symbiont interactions, and may provide a future basis for novel pest management strategy development. Here, we used a multitag 454 pyrosequencing approach to assess the bacterial endosymbiont diversity in larvae of four economically important <it>Otiorhynchus</it> species.</p> <p>Results</p> <p>High-throughput tag-encoded FLX amplicon pyrosequencing of a bacterial <it>16S</it> rDNA fragment was used to characterise bacterial communities associated with different <it>Otiorhynchus</it> spp. larvae. By sequencing a total of ~48,000 PCR amplicons, we identified 49 different operational taxonomic units (OTUs) as bacterial endosymbionts in the four studied <it>Otiorhynchus</it> species. More than 90% of all sequence reads belonged either to the genus <it>Rickettsia</it> or showed homology to the phylogenetic group of “<it>Candidatus</it> Blochmannia” and to endosymbionts of the lice <it>Pedicinus obtusus</it> and <it>P. badii</it>. By using specific primers for the genera <it>Rickettsia</it> and “<it>Candidatus</it> Blochmannia”, we identified a new phylogenetic clade of <it>Rickettsia</it> as well as “<it>Candidatus</it> Nardonella” endosymbionts in <it>Otiorhynchus</it> spp. which are closely related to “<it>Candidatus</it> Blochmannia” bacteria.</p> <p>Conclusions</p> <p>Here, we used multitag 454 pyrosequencing for assessment of insect endosymbiotic communities in weevils. As 454 pyrosequencing generates only quite short sequences, results of such studies can be regarded as a first step towards identifying respective endosymbiotic species in insects. In the second step of our study, we analysed sequences of specific gene regions for a more detailed phylogeny of selected endosymbiont genera. As a result we identified the presence of <it>Rickettsia</it> and “<it>Candidatus</it> Nardonella<it>”</it> endosymbionts in <it>Otiorhynchus</it> spp.. This knowledge is an important step in exploring bacteria-insect associations for potential use in insect pest control.</p

A Medicinal Herb Scutellaria lateriflora Inhibits PrP Replication in vitro and Delays the Onset of Prion Disease in Mice

Transmissible spongiform encephalopathies (TSE) are characterized by the misfolding of the host encoded prion protein (PrPC) into a pathogenic isoform (PrPSc) which leads to the accumulation of β-sheet-rich fibrils and subsequent loss of neurons and synaptic functions. Although many compounds have been identified which inhibit accumulation or dissolve fibrils and aggregates in vitro there is no therapeutic treatment to stop these progressive neurodegenerative diseases. Here we describe the effects of the traditional medicinal herb Scutellaria lateriflora (S. lateriflora) and its natural compounds, the flavonoids baicalein and baicalin, on the development of prion disease using in vitro and in vivo models. S. lateriflora extract as well as both constituents reduced the PrPres accumulation in scrapie-infected cell cultures and cell-free conversion assays and lead to the destabilization of pre-existing PrPSc fibrils. Moreover, tea prepared from S. lateriflora, prolonged significantly the incubation time of scrapie-infected mice upon oral treatment. Therefore S. lateriflora extracts as well as the individual compounds can be considered as promising candidates for the development of new therapeutic drugs against TSEs and other neurodegenerative diseases like Alzheimer’s and Parkinson’s disease

SLAP: Improving Physical Adversarial Examples with Short-Lived Adversarial Perturbations

Research into adversarial examples (AE) has developed rapidly, yet static adversarial patches are still the main technique for conducting attacks in the real world, despite being obvious, semi-permanent and unmodifiable once deployed. In this paper, we propose Short-Lived Adversarial Perturbations (SLAP), a novel technique that allows adversaries to realize physically robust real-world AE by using a light projector. Attackers can project a specifically crafted adversarial perturbation onto a real-world object, transforming it into an AE. This allows the adversary greater control over the attack compared to adversarial patches: (i) projections can be dynamically turned on and off or modified at will, (ii) projections do not suffer from the locality constraint imposed by patches, making them harder to detect. We study the feasibility of SLAP in the self-driving scenario, targeting both object detector and traffic sign recognition tasks, focusing on the detection of stop signs. We conduct experiments in a variety of ambient light conditions, including outdoors, showing how in non-bright settings the proposed method generates AE that are extremely robust, causing misclassifications on state-of-the-art networks with up to 99% success rate for a variety of angles and distances. We also demostrate that SLAP-generated AE do not present detectable behaviours seen in adversarial patches and therefore bypass SentiNet, a physical AE detection method. We evaluate other defences including an adaptive defender using adversarial learning which is able to thwart the attack effectiveness up to 80% even in favourable attacker conditions.Comment: 13 pages, to be published in Usenix Security 2021, project page https://github.com/ssloxford/short-lived-adversarial-perturbation

In Pursuit of Aviation Cybersecurity: Experiences and Lessons From a Competitive Approach

The passive and independent localization of aircraft has been the subject of much cyberphysical security research. We designed a multistage open competition focusing on the offline batch localization problem using opportunistic data sources. We discuss setup, results, and lessons learned