4,003 research outputs found
The Web SSO Standard OpenID Connect: In-Depth Formal Security Analysis and Security Guidelines
Web-based single sign-on (SSO) services such as Google Sign-In and Log In
with Paypal are based on the OpenID Connect protocol. This protocol enables
so-called relying parties to delegate user authentication to so-called identity
providers. OpenID Connect is one of the newest and most widely deployed single
sign-on protocols on the web. Despite its importance, it has not received much
attention from security researchers so far, and in particular, has not
undergone any rigorous security analysis.
In this paper, we carry out the first in-depth security analysis of OpenID
Connect. To this end, we use a comprehensive generic model of the web to
develop a detailed formal model of OpenID Connect. Based on this model, we then
precisely formalize and prove central security properties for OpenID Connect,
including authentication, authorization, and session integrity properties.
In our modeling of OpenID Connect, we employ security measures in order to
avoid attacks on OpenID Connect that have been discovered previously and new
attack variants that we document for the first time in this paper. Based on
these security measures, we propose security guidelines for implementors of
OpenID Connect. Our formal analysis demonstrates that these guidelines are in
fact effective and sufficient.Comment: An abridged version appears in CSF 2017. Parts of this work extend
the web model presented in arXiv:1411.7210, arXiv:1403.1866,
arXiv:1508.01719, and arXiv:1601.0122
Analyzing the BrowserID SSO System with Primary Identity Providers Using an Expressive Model of the Web
BrowserID is a complex, real-world Single Sign-On (SSO) System for web
applications recently developed by Mozilla. It employs new HTML5 features (such
as web messaging and web storage) and cryptographic assertions to provide
decentralized login, with the intent to respect users' privacy. It can operate
in a primary and a secondary identity provider mode. While in the primary mode
BrowserID runs with arbitrary identity providers (IdPs), in the secondary mode
there is one IdP only, namely Mozilla's default IdP.
We recently proposed an expressive general model for the web infrastructure
and, based on this web model, analyzed the security of the secondary IdP mode
of BrowserID. The analysis revealed several severe vulnerabilities.
In this paper, we complement our prior work by analyzing the even more
complex primary IdP mode of BrowserID. We do not only study authentication
properties as before, but also privacy properties. During our analysis we
discovered new and practical attacks that do not apply to the secondary mode:
an identity injection attack, which violates a central authentication property
of SSO systems, and attacks that break an important privacy promise of
BrowserID and which do not seem to be fixable without a major redesign of the
system. Some of our attacks on privacy make use of a browser side channel that
has not gained a lot of attention so far.
For the authentication bug, we propose a fix and formally prove in a slight
extension of our general web model that the fixed system satisfies all the
requirements we consider. This constitutes the most complex formal analysis of
a web application based on an expressive model of the web infrastructure so
far.
As another contribution, we identify and prove important security properties
of generic web features in the extended web model to facilitate future analysis
efforts of web standards and web applications.Comment: arXiv admin note: substantial text overlap with arXiv:1403.186
An Expressive Model for the Web Infrastructure: Definition and Application to the BrowserID SSO System
The web constitutes a complex infrastructure and as demonstrated by numerous
attacks, rigorous analysis of standards and web applications is indispensable.
Inspired by successful prior work, in particular the work by Akhawe et al. as
well as Bansal et al., in this work we propose a formal model for the web
infrastructure. While unlike prior works, which aim at automatic analysis, our
model so far is not directly amenable to automation, it is much more
comprehensive and accurate with respect to the standards and specifications. As
such, it can serve as a solid basis for the analysis of a broad range of
standards and applications.
As a case study and another important contribution of our work, we use our
model to carry out the first rigorous analysis of the BrowserID system (a.k.a.
Mozilla Persona), a recently developed complex real-world single sign-on system
that employs technologies such as AJAX, cross-document messaging, and HTML5 web
storage. Our analysis revealed a number of very critical flaws that could not
have been captured in prior models. We propose fixes for the flaws, formally
state relevant security properties, and prove that the fixed system in a
setting with a so-called secondary identity provider satisfies these security
properties in our model. The fixes for the most critical flaws have already
been adopted by Mozilla and our findings have been rewarded by the Mozilla
Security Bug Bounty Program.Comment: An abridged version appears in S&P 201
Baryon Asymmetry and Gravitational Waves from Pseudoscalar Inflation
In models of inflation driven by an axion-like pseudoscalar field, the
inflaton, a, may couple to the standard model hypercharge via a
Chern-Simons-type interaction, . This
coupling results in explosive gauge field production during inflation,
especially at its last stage, which has interesting phenomenological
consequences: For one thing, the primordial hypermagnetic field is maximally
helical. It is thus capable of sourcing the generation of nonzero baryon
number, via the standard model chiral anomaly, around the time of electroweak
symmetry breaking. For another thing, the gauge field production during
inflation feeds back into the primordial tensor power spectrum, leaving an
imprint in the stochastic background of gravitational waves (GWs). In this
paper, we focus on the correlation between these two phenomena. Working in the
approximation of instant reheating, we (1) update the investigation of
baryogenesis via hypermagnetic fields from pseudoscalar inflation and (2)
examine the corresponding implications for the GW spectrum. We find that
successful baryogenesis requires a suppression scale Lambda of around Lambda ~
3 x 10^17 GeV, which corresponds to a relatively weakly coupled axion. The
gauge field production at the end of inflation is then typically accompanied by
a peak in the GW spectrum at frequencies in the MHz range or above. The
detection of such a peak is out of reach of present-day technology; but in the
future, it may serve as a smoking-gun signal for baryogenesis from pseudoscalar
inflation. Conversely, models that do yield an observable GW signal suffer from
the overproduction of baryon number, unless the reheating temperature is lower
than the electroweak scale.Comment: 37 pages + references, 9 figures, 1 tabl
Catalog of infrared observations. Part 2: Appendixes
The Catalog of Infrared Observations (CIO) is a compilation of infrared astronomical observational data obtained from an extensive literature search of astronomical journals and major astronomical catalogs and surveys. The literature searches are complete for years 1965 to 1986. Supporting appendixes are published in this part. The appendices include an atlas of infrared source positions, two bibliographies of infrared literature upon which the search was based, and, keyed to the main Catalog listings (organized alphabetically by first author, and by date), an atlas of infrared spectral ranges, and IRAS data for the CIO sources. The complete CIO database is available to qualified users in printed microfiche and magnetic tape formats
Catalog of infrared observations. Part 1: Data
The Catalog of Infrared Observations (CIO) is a compilation of infrared astronomical observational data obtained from an extensive literature search of astronomical journals and major astronomical catalogs and surveys. The literature searches are complete for 1965 through 1986 in this Second Edition. The Catalog is published in two parts, with the observational data (roughly 200,000 observations of 20,000 individual sources) listed in Part I, and supporting appendices in Part II. The expanded Second Edition contains a new feature: complete IRAS 4-band data for all CIO sources detected, listed with the main Catalog observations, as well as in complete detail in the Appendix. The appendices include an atlas of infrared source positions, two bibliographies of infrared literature upon which the search was based, and, keyed to the main Catalog listings (organized alphabetically by author and then chronologically), an atlas of infrared spectral ranges, and IRAS data from the CIO sources. The complete CIO database is available to qualified users in printed microfiche and magnetic tape formats
Far infrared supplement: Catalog of infrared observations, second edition
The Far Infrared Supplement: Catalog of Infrared Observations summarizes all infrared astronomical observations at far infrared wavelengths (5 to 1000 microns) published in the scientific literature from 1965 through 1986. The Supplement list contain 25 percent of the observations in the full Catalog of Infrared Observations (CIO), and essentially eliminates most visible stars from the listings. The Supplement is thus more compact than the main catalog, and is intended for easy reference during astronomical observations. The Far Infrared Supplement (2nd Edition) includes the Index of Infrared Source Positions and the Bibliography of Infrared Astronomy for the subset of far infrared observations listed
Relational Sociology on a Global Scale: Field-Theoretical Perspectives on Cross-Cultural Comparison and the Re-Figuration of Space(s)
Der Vergleich, obwohl eines der grundlegendsten Verfahren der Sozialwissenschaften, ist alles andere als eine unumstrittene Methode. Tatsächlich existiert nach wie vor ein enorm heterogenes Feld vergleichender Ansätze, die jeweils auf unterschiedliche intellektuelle Traditionen, verschiedenartige Verständnisse des "Vergleichens", spezifische Probleme und Forschungsstrategien bezogen sind. Verschiedene, auf ihre jeweilige Weise hochentwickelte komparative Forschungsrichtungen stehen so weitgehend unverbunden nebeneinander, wodurch letztlich analytische Potenziale verschenkt werden: ländervergleichende (häufig mit quantitativen Verfahren und erklärenden Zielsetzungen verknüpfte) Studien einerseits und kulturvergleichende (typischerweise mit qualitativen Verfahren und verstehend-hermeneutischen Anliegen verbundene) Ansätze andererseits. Die modernen Sozialwissenschaften sehen sich indes mit einer zunehmend komplexen globalen Wirklichkeit konfrontiert, die sich weniger als je zuvor adäquat auf der Grundlage einseitiger Referenzsysteme erfassen lässt. Vor diesem Hintergrund entwickeln wir in diesem Beitrag die Sozialraum- und Feldtheorie Pierre BOURDIEUs durch eine konsequent relationale Lesart in eine Richtung weiter, die es erlaubt, unterschiedliche Konzeptionen und Techniken des sozialwissenschaftlichen Vergleichs im Rahmen eines einheitlichen Bezugsrahmens zur Geltung zu bringen. Der Rückgriff auf diesen allgemeinen Bezugsrahmen eröffnet die Möglichkeit, nationale, internationale sowie transnationale Vergleiche anzustellen, ohne dabei die jeweiligen Referenzsysteme und die damit korrespondierenden Vergleichsentitäten essenzialisieren oder hypostasieren zu müssen.Comparison, as a fundamental operation in the social sciences, is anything but a clearly defined method. Rather, there is a highly heterogeneous field of comparative approaches with different intellectual traditions, ideas of "comparison," specific problems, and research strategies. In fact, different streams of comparative studies exist in parallel, each highly elaborated in its own way but largely ignoring the achievements of the other tradition and thus ultimately wasting analytical potential—namely cross-national studies (often associated with quantitative methods and explanatory objectives) on the one hand and cross-cultural studies or cultural comparisons (usually associated with qualitative methods and hermeneutical approaches) on the other. However, contemporary social sciences are confronted with an increasingly complex global reality that can no longer be described on the basis of one-dimensional frames of reference. Drawing on the basic methodological principle of relationality, the aim of our article is to develop Pierre BOURDIEU's theory of fields and social spaces in a direction that allows different approaches to comparison to be made fruitful on the basis of a common frame of reference. Based on this generalized framework, national, international, and transnational comparisons become possible without having to essentialize or hypostasize specific reference frames and corresponding units of analysis
Interpersonal sensorimotor contingencies: Information-theoretic relevance of subjective experience
Peer reviewedFinal Published versio
Far infrared supplement. Third edition: Catalog of infrared observations (lambda greater than or equal to 4.6 micrometers)
The Far Infrared Supplement contains a subset of the data in the full Catalog of Infrared Observations (all observations at wavelengths greater than 4.6 microns). The Catalog of Infrared Observations (CIO), NASA RP-1294, is a compilation of infrared astronomical observational data obtained from an extensive literature search of scientific journals and major astronomical catalogs and surveys. The literature search is complete for years 1965 through 1990 in this third edition. The catalog contains about 210,000 observations of roughly 20,000 individual sources, and supporting appendices. The expanded third edition contains coded IRAS 4-band data for all CIO sources detected by IRAS. The appendices include an atlas of infrared source positions (also included in this volume), two bibliographies of catalog listings, and an atlas of infrared spectral ranges. The complete CIO database is available to qualified users in printed, microfiche, and magnetic tape formats
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