9,138 research outputs found
Secure SCTP against DoS attacks in wireless Internet
The Stream Control Transport Protocol (SCTP) is a new transport layer protocol that has been designed to provide reliable transport over the Internet. While the Transport Control Protocol (TCP) is the most popular transport protocol for the Internet, it falls short with regard to security, more specifically resilience to Denial-of-Service (DoS) attacks, such as SYN attacks. The need for resilience to DoS attacks is obvious, and SCTP provides for this resilience via its improved handshake mechanism and the Cookie feature. This paper discusses the SCTP simulation with particular emphasis on resilience to DoS attacks. As revealed by our detailed simulation study, the increased DoS resilience comes with increased overheads. While DoS resilience is extremely critical, reducing overheads in the resource-constrained wireless environment also assumes paramount importance. Hence we propose secure SCTP with an innovative Cookie mechanism using a combination of cache and INIT packet repetition to minimize the communication overhead and simultaneously to maximize security associated with SCTP's DoS resilience for wireless Internet.5th IFIP International Conference on Network Control & Engineering for QoS, Security and MobilityRed de Universidades con Carreras en Informática (RedUNCI
Denial-of-Service Resistance in Key Establishment
Denial of Service (DoS) attacks are an increasing problem for network connected systems. Key establishment protocols are applications that are particularly vulnerable to DoS attack as they are typically required to perform computationally expensive cryptographic operations in order to authenticate the protocol initiator and to generate the cryptographic keying material that will subsequently be used to secure the communications between initiator and responder. The goal of DoS resistance in key establishment protocols is to ensure that attackers cannot prevent a legitimate initiator and responder deriving cryptographic keys without expending resources beyond a responder-determined threshold. In this work we review the strategies and techniques used to improve resistance to DoS attacks. Three key establishment protocols implementing DoS resistance techniques are critically reviewed and the impact of misapplication of the techniques on DoS resistance is discussed. Recommendations on effectively applying resistance techniques to key establishment protocols are made
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
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
DTLS Performance in Duty-Cycled Networks
The Datagram Transport Layer Security (DTLS) protocol is the IETF standard
for securing the Internet of Things. The Constrained Application Protocol,
ZigBee IP, and Lightweight Machine-to-Machine (LWM2M) mandate its use for
securing application traffic. There has been much debate in both the
standardization and research communities on the applicability of DTLS to
constrained environments. The main concerns are the communication overhead and
latency of the DTLS handshake, and the memory footprint of a DTLS
implementation. This paper provides a thorough performance evaluation of DTLS
in different duty-cycled networks through real-world experimentation, emulation
and analysis. In particular, we measure the duration of the DTLS handshake when
using three duty cycling link-layer protocols: preamble-sampling, the IEEE
802.15.4 beacon-enabled mode and the IEEE 802.15.4e Time Slotted Channel
Hopping mode. The reported results demonstrate surprisingly poor performance of
DTLS in radio duty-cycled networks. Because a DTLS client and a server exchange
more than 10 signaling packets, the DTLS handshake takes between a handful of
seconds and several tens of seconds, with similar results for different duty
cycling protocols. Moreover, because of their limited memory, typical
constrained nodes can only maintain 3-5 simultaneous DTLS sessions, which
highlights the need for using DTLS parsimoniously.Comment: International Symposium on Personal, Indoor and Mobile Radio
Communications (PIMRC - 2015), IEEE, IEEE, 2015,
http://pimrc2015.eee.hku.hk/index.htm
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
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