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Receiver-Autonomous Spoofing Detection: Experimental Results of a Multi-antenna Receiver Defense Against a Portable Civil GPS Spoofer
In this work we demonstrate the use of a dual antenna
receiver that employs a receiver-autonomous angle-ofarrival
spoofing countermeasure. This defense is
conjectured to be effective against all but the most sophisticated spoofing attempts. The technique is based
on observation of L1 carrier differences between multiple
antennas referenced to a common oscillator.
We first employ a moderately sophisticated spoofer to
"fool" a single-antenna civil receiver. We then deploy the
same attack after augmenting the receiver with an
additional antenna and with receiver-autonomous spoofdetection
software. The work discusses the experimental
results together with various issues related to sensitivity,
probability of false alarm, impact of carrier multipath,
line-bias-calibration, and physical setup and security.
We suggest that this work is important to the community
as it provides experimental validation of a low-cost
technique for receiver-autonomous spoofing detection.
Furthermore, the technique, when combined with physical
security of the antenna installation, provides a strong
defense against even a sophisticated attack.
The receiver employed is an L1-only civil GPS receiver
with multiple antenna capability. The GPS chipset
employed is the venerable GP2015/GP2021 that has been
freely available for over a decade. As such, this receiver is
representative of many civil receivers in use today for a
variety of applications. Multiple antennas are enabled
either through multiple independent RF front ends and
correlators or via antenna multiplexing into a single RF
front end and correlator bank.Aerospace Engineering and Engineering Mechanic
Enhanced Obfuscation for Software Protection in Autonomous Vehicular Cloud Computing Platforms
Nowadays, sensors, communications connections, and more powerful computing capabilities are added to automobiles, making them more intelligent. The primary goal was to eliminate the need for human control, making them Autonomous Vehicles (AVs). Consequently, researchers thought to put all that newly added computational power to use for other endeavors. Hence, Autonomous Vehicular Cloud Computing (AVCC) models were introduced. Nevertheless, this goal is not an easy undertaking, the dynamic nature of autonomous vehicles introduces a critical challenge in the development of such a distributed computing platform. Furthermore, it presents far complicated issues as far as security and protection of services associated with this framework. In this paper, we center around securing programs running on AVCC. Here, we focus on timing side-channel attacks which aim to leak information about running code, which can be utilized to reverse engineer the program itself. We propose to mitigate these attacks via obfuscated compilation. In particular, we change the control flow of an input program at the compiler level, thereby changing the program’s apparent behavior and accompanying physical manifestations to hinder these attacks. We improve our previous ARM-based implementation to address its limitations and provide more comprehensive coverage for different programs. Our solution is software-based and generically portable - fitting different hardware platforms and numerous input program languages at the source level. Our findings prove a considerable improvement over our previous technique, which may provide more defense against timing side-channels
Bacterial mechanosensitive channels : progress towards an understanding of their roles in cell physiology
Open Access funded by Wellcome Trust Under a Creative Commons license Thanks to all members of the Aberdeen group, collaborators and friends whose discussions have spurred the development of the MS channel field. Special thanks to Doug Rees, Diane Newman and Rob Phillips for their support and hospitality at Caltech. Unique insights have been provided by members of the Newman and Phillips research groups, particularly, Caj Neubauer, Gargi Kulkarni and Megan Bergkessel, Heun Jin Lee and Maja Bialecka-Fornal. The author's research on MS channels is supported by a grant from The Wellcome Trust (WT092552MA) and the BBSRC (BB/H017917/1). The author is a Leverhulme Emeritus Fellow and this work was supported in part by a CEMI Visiting Faculty Fellowship from Caltech.Peer reviewedPublisher PD
DR.SGX: Hardening SGX Enclaves against Cache Attacks with Data Location Randomization
Recent research has demonstrated that Intel's SGX is vulnerable to various
software-based side-channel attacks. In particular, attacks that monitor CPU
caches shared between the victim enclave and untrusted software enable accurate
leakage of secret enclave data. Known defenses assume developer assistance,
require hardware changes, impose high overhead, or prevent only some of the
known attacks. In this paper we propose data location randomization as a novel
defensive approach to address the threat of side-channel attacks. Our main goal
is to break the link between the cache observations by the privileged adversary
and the actual data accesses by the victim. We design and implement a
compiler-based tool called DR.SGX that instruments enclave code such that data
locations are permuted at the granularity of cache lines. We realize the
permutation with the CPU's cryptographic hardware-acceleration units providing
secure randomization. To prevent correlation of repeated memory accesses we
continuously re-randomize all enclave data during execution. Our solution
effectively protects many (but not all) enclaves from cache attacks and
provides a complementary enclave hardening technique that is especially useful
against unpredictable information leakage
What drives farmers to make top-down or bottom-up adaptation to climate change and fluctuations?:A comparative study on 3 cases of apple farming in Japan and South Africa
Agriculture is one of the most vulnerable sectors to climate change. Farmers have been exposed to multiple stressors including climate change, and they have managed to adapt to those risks. The adaptation actions undertaken by farmers and their decision making are, however, only poorly understood. By studying adaptation practices undertaken by apple farmers in three regions: Nagano and Kazuno in Japan and Elgin in South Africa, we categorize the adaptation actions into two types: farmer initiated bottom-up adaptation and institution led top-down adaptation. We found that the driver which differentiates the type of adaptation likely adopted was strongly related to the farmers' characteristics, particularly their dependence on the institutions, e.g. the farmers' cooperative, in selling their products. The farmers who rely on the farmers' cooperative for their sales are likely to adopt the institution-led adaptation, whereas the farmers who have established their own sales channels tend to start innovative actions by bottom-up. We further argue that even though the two types have contrasting features, the combinations of the both types of adaptations could lead to more successful adaptation particularly in agriculture. This study also emphasizes that more farm-level studies for various crops and regions are warranted to provide substantial feedbacks to adaptation policy
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