BARTER: Profile Model Exchange for Behavior-Based Access Control and Communication Security in MANETs

There is a considerable body of literature and technology that provides access control and security of communication for Mobile Ad-hoc Networks (MANETs) based on cryptographic authentication technologies and protocols. We introduce a new method of granting access and securing communication in a MANET environment to augment, not replace, existing techniques. Previous approaches grant access to the MANET, or to its services, merely by means of an authenticated identity or a qualified role. We present BARTER, a framework that, in addition, requires nodes to exchange a model of their behavior to grant access to the MANET and to assess the legitimacy of their subsequent communication. This framework forces the nodes not only to say who or what they are, but also how they behave. BARTER will continuously run membership acceptance and update protocols to give access to and accept traffic only from nodes whose behavior model is considered "normal" according to the behavior model of the nodes in the MANET. We implement and experimentally evaluate the merger between BARTER and other cryptographic technologies and show that BARTER can implement a fully distributed automatic access control and update with small cryptographic costs. Although the methods proposed involve the use of content-based anomaly detection models, the generic infrastructure implementing the methodology may utilize any behavior model. Even though the experiments are implemented for MANETs, the idea of model exchange for access control can be applied to any type of network

BARTER: Behavior Profile Exchange for Behavior-Based Admission and Access Control in MANETs

Mobile Ad-hoc Networks (MANETs) are very dynamic networks with devices continuously entering and leaving the group. The highly dynamic nature of MANETs renders the manual creation and update of policies associated with the initial incorporation of devices to the MANET (admission control) as well as with anomaly detection during communications among members (access control) a very difficult task. In this paper, we present BARTER, a mechanism that automatically creates and updates admission and access control policies for MANETs based on behavior profiles. BARTER is an adaptation for fully distributed environments of our previously introduced BB-NAC mechanism for NAC technologies. Rather than relying on a centralized NAC enforcer, MANET members initially exchange their behavior profiles and compute individual local definitions of normal network behavior. During admission or access control, each member issues an individual decision based on its definition of normalcy. Individual decisions are then aggregated via a threshold cryptographic infrastructure that requires an agreement among a fixed amount of MANET members to change the status of the network. We present experimental results using content and volumetric behavior profiles computed from the ENRON dataset. In particular, we show that the mechanism achieves true rejection rates of 95% with false rejection rates of 9%

A Network Access Control Mechanism Based on Behavior Profiles

Current network access control (NAC) technologies manage the access of new devices into a network to prevent rogue devices from attacking network hosts or services. Typically, new devices are checked against a set of manually defined policies (rules) before being granted access by the NAC enforcer. The main difficulty with this approach lies in the generation and update of new policies manually as time elapses and all devices have to reestablish their access rights. The BB-NAC mechanism was the first to introduce a novel behavior-based network access control architecture based on behavior profiles and not rules, where behavior-based access control policies were automatically generated. As originally presented, BB-NAC relied on manually pre-determined clusters of behavior which required human intervention and prevented the fully automation of the mechanism. In this paper, we present an enhanced BB-NAC mechanism that fully automatizes the creation of clusters of behavior. The access control is enhanced with the incorporation of automatic behavior clustering, which improves the intrusion detection capabilities by allowing for a more fine-grained definition of normal behavior. Apart from the lack of automatic clustering, the original BB-NAC overlooked the evolution of the mechanism as new behavior profiles were computed over time. As part of our enhancements, we also present an incremental-learning algorithm that automatically updates the behavior-based access control policies. We show that the algorithm is resilient to compromised or fabricated profiles trying to manipulate the policies. We provide extensive experiments with real user profiles computed with their network flows processed from Cisco NetFlow logs captured at our host institution. Our results show that behavior-based access control policies enhance conventional NAC technologies. Specifically, we achieve true rejection rates of 95% for anomalous user profiles separated by one standard deviation from the normal user network behavior. In addition, we also show that the enhanced mechanism can differentiate between normal changes in the behavior profiles (concept drift) and attacks

Behavior-Profile Clustering for False Alert Reduction in Anomaly Detection Sensors

Anomaly detection (AD) sensors compute behavior profiles to recognize malicious or anomalous activities. The behavior of a host is checked continuously by the AD sensor and an alert is raised when the behavior deviates from its behavior profile. Unfortunately, the majority of AD sensors suffer from high volumes of false alerts either maliciously crafted by the host or originating from insufficient training of the sensor. We present a cluster-based AD sensor that relies on clusters of behavior profiles to identify anomalous behavior. The behavior of a host raises an alert only when a group of host profiles with similar behavior (cluster of behavior profiles) detect the anomaly, rather than just relying on the host's own behavior profile to raise the alert (single-profile AD sensor). A cluster-based AD sensor significantly decreases the volume of false alerts by providing a more robust model of normal behavior based on clusters of behavior profiles. Additionally, we introduce an architecture designed for the deployment of cluster-based AD sensors. The behavior profile of each network host is computed by its closest switch that is also responsible for performing the anomaly detection for each of the hosts in its subnet. By placing the AD sensors at the switch, we eliminate the possibility of hosts crafting malicious alerts. Our experimental results based on wireless behavior profiles from users in the CRAWDAD dataset show that the volume of false alerts generated by cluster-based AD sensors is reduced by at least 50% compared to single-profile AD sensors

Gastroethnobotany of Halophytes

The halophytes are a specialized group of plants among which there are some representatives that have been cultivated for millenia. Domesticated or wild lineages are also consumed as food, being chard and dates fruits a good example of it. Other species highly appreciated and consumed locally are collected from wild, like Crithmum, and form part of the traditional cuisine of various areas of the planet. Within this group, some are the object of global cultivation and are distributed by haute cuisine networks such as Salicornia, Mertensia, or Tetragonia. Finally, there are other wild halophytes that were only consumed in situations of extreme need such as famines. Generally, they have not been appreciated by the populations that collect them, such as Halosarcia, Suaeda, or Arthrocnemum. The case of Tetragonia, a species native to Australia, is very significant. The perception of the aborigines, who did not eat it, was different from that of the European settlers who did consume them and even sent their seeds to Europe for domestication and cultivation as new vegetable. Currently, the new gastronomy, sometimes based on tradition and others on experimentation itself, has incorporated into the kitchen many news halophytes and with them has developed numerous unpublished and novel recipes

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO

Confirmation of the utility of the International Staging System and identification of a unique pattern of disease in Brazilian patients with multiple myeloma

Santa Casa São Paulo, São Paulo, BrazilUniv Fed Rio de Janeiro, Rio de Janeiro, BrazilUniv São Paulo, São Paulo, BrazilHEMOPE, Recife, PE, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilUniv Fed Bahia, BR-41170290 Salvador, BA, BrazilHosp Brigadeiro São Paulo, São Paulo, BrazilUniv Fed Rio Grande do Sul, BR-90046900 Porto Alegre, RS, BrazilSch Med, Ribeirao Preto, BrazilUniv Fed Minas Gerais, Belo Horizonte, MG, BrazilUniv Fed Parana, BR-80060000 Curitiba, Parana, BrazilUniv Estadual Campinas, BR-13081970 Campinas, SP, BrazilInst Nacl Canc Rio Janeiro, Rio de Janeiro, BrazilCanc Res & Biostat, Seattle, WA USACedars Sinai Outpatient Canc Ctr, Aptium Oncol Inc, Los Angeles, CA USAUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc

Mobile Personal Healthcare System for Non-Invasive, Pervasive and Continuous Blood Pressure Monitoring: A Feasibility Study

Background: Smartphone-based blood pressure (BP) monitor using photoplethysmogram (PPG) technology has emerged as a promising approach to empower users with self-monitoring for effective diagnosis and control ofhypertension (HT). Objective: This study aimed to develop a mobile personal healthcare system for non-invasive, pervasive, and continuous estimation of BP level and variability to be user-friendly to elderly. Methods: The proposed approach was integrated by a self-designed cuffless, calibration-free, wireless and wearable PPG-only sensor, and a native purposely-designed smartphone application using multilayer perceptron machine learning techniques from raw signals. We performed a pilot study with three elder adults (mean age 61.3 ± 1.5 years; 66% women) to test usability and accuracy of the smartphone-based BP monitor. Results: The employed artificial neural network (ANN) model performed with high accuracy in terms of predicting the reference BP values of our validation sample (n=150). On average, our approach predicted BP measures with accuracy \u3e90% and correlations \u3e0.90 (P \u3c .0001). Bland-Altman plots showed that most of the errors for BP prediction were less than 10 mmHg. Conclusions: With further development and validation, the proposed system could provide a cost-effective strategy to improve the quality and coverage of healthcare, particularly in rural zones, areas lacking physicians, and solitary elderly populations

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO