26,179 research outputs found
DTKI: a new formalized PKI with no trusted parties
The security of public key validation protocols for web-based applications
has recently attracted attention because of weaknesses in the certificate
authority model, and consequent attacks.
Recent proposals using public logs have succeeded in making certificate
management more transparent and verifiable. However, those proposals involve a
fixed set of authorities. This means an oligopoly is created. Another problem
with current log-based system is their heavy reliance on trusted parties that
monitor the logs.
We propose a distributed transparent key infrastructure (DTKI), which greatly
reduces the oligopoly of service providers and allows verification of the
behaviour of trusted parties. In addition, this paper formalises the public log
data structure and provides a formal analysis of the security that DTKI
guarantees.Comment: 19 page
Do not trust me: Using malicious IdPs for analyzing and attacking Single Sign-On
Single Sign-On (SSO) systems simplify login procedures by using an an
Identity Provider (IdP) to issue authentication tokens which can be consumed by
Service Providers (SPs). Traditionally, IdPs are modeled as trusted third
parties. This is reasonable for SSO systems like Kerberos, MS Passport and
SAML, where each SP explicitely specifies which IdP he trusts. However, in open
systems like OpenID and OpenID Connect, each user may set up his own IdP, and a
discovery phase is added to the protocol flow. Thus it is easy for an attacker
to set up its own IdP. In this paper we use a novel approach for analyzing SSO
authentication schemes by introducing a malicious IdP. With this approach we
evaluate one of the most popular and widely deployed SSO protocols - OpenID. We
found four novel attack classes on OpenID, which were not covered by previous
research, and show their applicability to real-life implementations. As a
result, we were able to compromise 11 out of 16 existing OpenID implementations
like Sourceforge, Drupal and ownCloud. We automated discovery of these attacks
in a open source tool OpenID Attacker, which additionally allows fine-granular
testing of all parameters in OpenID implementations. Our research helps to
better understand the message flow in the OpenID protocol, trust assumptions in
the different components of the system, and implementation issues in OpenID
components. It is applicable to other SSO systems like OpenID Connect and SAML.
All OpenID implementations have been informed about their vulnerabilities and
we supported them in fixing the issues
Secure multi-party computation for analytics deployed as a lightweight web application
We describe the definition, design, implementation, and deployment of a secure multi-party computation protocol and web application. The protocol and application allow groups of cooperating parties with minimal expertise and no specialized resources to compute basic statistical analytics on their collective data sets without revealing the contributions of individual participants. The application was developed specifically to support a Boston Women’s Workforce Council (BWWC) study of wage disparities within employer organizations in the Greater Boston Area. The application has been deployed successfully to support two data collection sessions (in 2015 and in 2016) to obtain data pertaining to compensation levels across genders and demographics. Our experience provides insights into the particular security and usability requirements (and tradeoffs) a successful “MPC-as-a-service” platform design and implementation must negotiate.We would like to acknowledge all the members of the Boston Women’s Workforce Council, and to thank in particular MaryRose Mazzola, Christina M. Knowles, and Katie A. Johnston, who led the efforts to organize participants and deploy the protocol as part of the 100% Talent: The Boston Women’s Compact [31], [32] data collections. We also thank the Boston University Initiative on Cities (IOC), and in particular Executive Director Katherine Lusk, who brought this potential application of secure multi-party computation to our attention. The BWWC, the IOC, and several sponsors contributed funding to complete this work. Support was also provided in part by Smart-city Cloud-based Open Platform and Ecosystem (SCOPE), an NSF Division of Industrial Innovation and Partnerships PFI:BIC project under award #1430145, and by Modular Approach to Cloud Security (MACS), an NSF CISE CNS SaTC Frontier project under award #1414119
Proving Properties of Rich Internet Applications
We introduce application layer specifications, which allow us to reason about
the state and transactions of rich Internet applications. We define variants of
the state/event based logic UCTL* along with two example applications to
demonstrate this approach, and then look at a distributed, rich Internet
application, proving properties about the information it stores and
disseminates. Our approach enables us to justify proofs about abstract
properties that are preserved in the face of concurrent, networked inputs by
proofs about concrete properties in an Internet setting. We conclude that our
approach makes it possible to reason about the programs and protocols that
comprise the Internet's application layer with reliability and generality.Comment: In Proceedings WWV 2013, arXiv:1308.026
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