Compartmentation policies for Android apps:A combinatorial optimization approach

Some smartphone platforms such as Android have a distinctive message passing system that allows for sophisticated interactions among app components, both within and across app boundaries. This gives rise to various security and privacy risks, including not only intentional collusion attacks via permission re-delegation but also inadvertent disclosure of information and service misuse through confused deputy attacks. In this paper, we revisit the perils of app coexistence in the same platform and propose a risk mitigation mechanism based on segregating apps into isolated groups following classical security compartmentation principles. Compartments can be implemented using lightweight approaches such as Inter-Component Communication (ICC) firewalling or through virtualization, effectively fencing off each group of apps. We then leverage recent works on quantified risk metrics for Android apps to couch compartmentation as a combinatorial optimization problem akin to the classical bin packing or knapsack problems. We study a number of simple yet effective numerical optimization heuristics, showing that very good compartmentation solutions can be obtained for the problem sizes expected in current’s mobile environments

Detecting Targeted Smartphone Malware with Behavior-Triggering Stochastic Models

none4sinoneGuillermo Suarez-Tangil; Mauro Conti; Juan E. Tapiador; and Pedro Peris-LopezGuillermo Suarez, Tangil; Conti, Mauro; Juan E., Tapiador; Pedro Peris, Lope

Hindering data theft with encrypted data trees

Data theft is a major threat for modern organizations with potentially large economic consequences. Although these attacks may well originate outside an organization’s information systems, the attacker—or else an insider—must even-tually make contact with the system where the information resides and extract it. In this work, we propose a scheme that hinders unauthorized data extraction by modifying the basic file system primitives used to access files. Intuitively, our proposal emulates the chains used to protect valuable items in certain clothing shopping centers, where shoplifting is prevented by forcing the thief to steal the whole rack of items. We achieve this by encrypting sensitive files using nonces (i.e., pseudorandom numbers used only once) as keys. Such nonces are available, also in encrypted form, in other objects of the file system. The system globally resembles a distributed Merkle hash tree, in such a way that getting access to a file requires previous access to a number of other files. This forces any potential attacker to extract not only the targeted sensitive information, but also all the files chained to it that are necessary to compute the associated key. Further-more, our scheme incorporates a probabilistic rekeying mechanism to limit the damage that might be caused by patient extractors. We report experimental results measuring the time overhead introduced by our proposal and compare it with the effort an attacker would need to successfully extract information from the system. Our results show that the scheme increases substantially the effort required by an insider, while the introduced overhead is feasible for standard computing platforms

Non-invasive multi-modal human identification system combining ECG, GSR, and airflow biosignals

A huge amount of data can be collected through a wide variety of sensor technologies. Data mining techniques are often useful for the analysis of gathered data. This paper studies the use of three wearable sensors that monitor the electrocardiogram, airflow, and galvanic skin response of a subject with the purpose of designing an efficient multi-modal human identification system. The proposed system, based on the rotation forest ensemble algorithm, offers a high accuracy (99.6 % true acceptance rate and just 0.1 % false positive rate). For its evaluation, the proposed system was testing against the characteristics commonly demanded in a biometric system, including universality, uniqueness, permanence, and acceptance. Finally, a proof-of-concept implementation of the system is demonstrated on a smartphone and its performance is evaluated in terms of processing speed and power consumption. The identification of a sample is extremely efficient, taking around 200 ms and consuming just a few millijoules. It is thus feasible to use the proposed system on a regular smartphone for user identification.This work was supported by MINECO grant TIN2013- 46469-R (SPINY: Security and Privacy in the Internet of You) and CAM grant S2013/ICE-3095 (CIBERDINE: Cybersecurity, Data, and Risks)

Análisis petrográficos de rocas silíceas en el centro-este de la provincia de San Luis

En este trabajo se presentan los primeros resultados obtenidos en la caracterización de la Base Regional de Recursos Líticos en las cuencas alta y media del río Quinto (centro-este de la Provincia de San Luis). Los trabajos de campo fueron planificados desde la arqueológica distribucional y la geoarqueología, con el objetivo de localizar fuentes de materia prima lítica potenciales y aquellas utilizadas por los grupos locales. A nivel macroregional, el cuarzo es la principal materia prima lítica registrada en sitios arqueológicos. Sin embargo, los antecedentes arqueológicos mencionan la utilización de rocas silíceas de calidad superior para la talla. En este sentido, solo tres fuentes de este tipo fueron sistemáticamente estudiadas en la provincia. El análisis petrográfico permitió determinar la presencia de tres nuevas fuentes potenciales de rocas silíceas, identificadas microscópicamente como calcedonias.Neste artigo, apresentamos os primeiros resultados obtidos na caracterização da Base Regional de Recursos Lógicos nas bacias superior e média do rio Quinto (leste central da Província de San Luis). Os trabalhos de campo foram planejados a partir da arqueologia e geoarqueologia distributiva, com o objetivo de localizar fontes de matérias-primas líticas potenciais e as utilizadas pelos grupos locais. No nível macrorregional, o quartzo é a principal matéria-prima lítica registrada em sítios arqueológicos. No entanto, o registro arqueológico mencionou o uso de rochas siliciosas de qualidade superior para o tamanho. Nesse sentido, apenas três fontes deste tipo foram estudadas sistematicamente na província. A análise petrográfica permitiu determinar a presença de três novas fontes potenciais de rochas silíceas, identificadas microscopicamente como calcedônia.In this paper we present the first results obtained in the characterization of the Regional Base of Lithic Resources in the upper and middle basins of the Quinto River (east-central of the Province of San Luis). The field works were planned from the distributional archeology and geoarchaeology, with the aim of locating sources of potential lithic raw material and those used by local groups. At the macroregional level, quartz is the main lithic raw material registered in archaeological sites. However, the archaeological record mentioned the use of siliceous rocks of superior quality for the size. In this sense, only three sources of this type were systematically studied in the province. The petrographic analysis allowed to determine the presence of three new potential sources of siliceous rocks, identified microscopically as chalcedonies.Fil: Borgo, Mariangeles. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; ArgentinaFil: Ramos, Gabriel Alejandro. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Geología; ArgentinaFil: Heider, Guillermo. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; ArgentinaFil: Chiesa, Jorge Orlando. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Geología; ArgentinaFil: Ortiz Suarez, Ariel Emilio. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Geología; ArgentinaFil: Curtoni, Rafael Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Gil, Raul Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; Argentin

Geoarchaeological studies of sources and lithic quarries in the Pampean Sierras and adjacent plains

El material lítico es el elemento de mayor abundancia en los registros arqueológicos de Sierras Centrales y sus llanuras adyacentes. Los estudios realizados sobre el mismo utilizan diferentes escalas espaciales, metodologías de campo y laboratorio. Sin embargo, los programas de investigación orientados a la detección de fuentes de aprovisionamiento y canteras arqueológicas no tienen en la región un desarrollo similar al de otras regiones del Argentina. En este trabajo se presentan las líneas iniciales de un proyecto de escala macrorregional, específicamente orientado a su estudio. Los resultados alcanzados hasta el momento permitieron identificar numerosas canteras y fuentes en las provincias de San Luis, Córdoba, La Rioja y Catamarca. En ese marco, proponemos un modelo de yacencia de rocas silíceas. El mismo permite entender por un lado la génesis de las rocas identificadas y, por otra parte, se constituye como el primer modelo predictivo de escala amplia para el centro de Argentina.Lithic materials are among the most abundant items in the archaeological record of the Central Ranges and their adjacent plains. The studies carried out with lithic artefacts use different spatial scales, as well as field and laboratory methodologies. However, the research programs oriented to the detection of lithic sources and archaeological quarries do not have in this region a similar development in comparison to other regions of Argentina. This paper presents the initial lines of a macroregional scale project, specifically oriented to their study. The results achieved so far allowed the identification of numerous quarries and lithic sources in San Luis, Córdoba, La Rioja, and Catamarca provinces. We propose a model of deposit of the siliceous rocks which allows to understand the genesis of the identified rocks. On the other hand, it is the first wide-scale predictive occurrence model for the center of Argentina.Fil: Heider, Guillermo. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; ArgentinaFil: Ortiz Suarez, Ariel. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Geología; ArgentinaFil: Rivero, Diego Eduardo. Centro de Estudios Históricos "Profesor Carlos S. A. Segreti". Instituto de Estudios Históricos - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Estudios Históricos; ArgentinaFil: Baldo, Edgardo Gaspar Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Pastor, Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Catamarca. Universidad Nacional de Catamarca. Centro de Investigaciones y Transferencia de Catamarca; ArgentinaFil: Ramos, Gabriel. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Geología; ArgentinaFil: Borgo, Mariangeles. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; ArgentinaFil: Gil, Raul Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Chiesa, Jorge. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Geología; ArgentinaFil: Costa, Carlos. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Geología; ArgentinaFil: Recalde, Maria Andrea. Centro de Estudios Historicos "prof. Carlos S.a. Segreti". Instituto de Estudios Historicos. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Estudios Historicos.; ArgentinaFil: Curtoni, Rafael Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Capriolo, Ana Julieta. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; ArgentinaFil: Muñoz, Lucas. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Geología; Argentin

Hindering data theft with encrypted data trees

Data theft is a major threat for modern organizations with potentially large economic consequences. Although these attacks may well originate outside an organization’s information systems, the attacker—or else an insider—must even-tually make contact with the system where the information resides and extract it. In this work, we propose a scheme that hinders unauthorized data extraction by modifying the basic file system primitives used to access files. Intuitively, our proposal emulates the chains used to protect valuable items in certain clothing shopping centers, where shoplifting is prevented by forcing the thief to steal the whole rack of items. We achieve this by encrypting sensitive files using nonces (i.e., pseudorandom numbers used only once) as keys. Such nonces are available, also in encrypted form, in other objects of the file system. The system globally resembles a distributed Merkle hash tree, in such a way that getting access to a file requires previous access to a number of other files. This forces any potential attacker to extract not only the targeted sensitive information, but also all the files chained to it that are necessary to compute the associated key. Further-more, our scheme incorporates a probabilistic rekeying mechanism to limit the damage that might be caused by patient extractors. We report experimental results measuring the time overhead introduced by our proposal and compare it with the effort an attacker would need to successfully extract information from the system. Our results show that the scheme increases substantially the effort required by an insider, while the introduced overhead is feasible for standard computing platforms

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