146 research outputs found
Kerberos based authentication for inter-domain roaming in wireless heterogeneous network
AbstractAn increased demand in ubiquitous high speed wireless access has led integration of different wireless technologies provided by different administrative domains creating truly a heterogeneous network. Security is one of the major hurdles in such network environment. As a mobile station moves in and out of the coverage area of one wireless network to another, it needs to be authenticated. The existing protocols for authentication of a mobile station are typically centralized, where the home network participates in each authentication process. It requires home network to maintain roaming agreement with all other visiting networks. Moreover, the round trip time to home network results high latency. This paper is focused on developing authentication protocol for wireless network irrespective of the technologies or the administrative domain. We propose a secure protocol which adopts strong features of Kerberos based on tickets for rigorous mutual authentication and session key establishment along with issuance of token so that the mobile station can have access to not only the roaming partner of home network but also to the roaming partner of previous visited networks. The performance evaluation and comparative analysis of the proposed protocol is carried out with the already implemented standard protocols and most remarkable research works till date to confirm the solidity of the results presented
Energy Efficient Security Framework for Wireless Local Area Networks
Wireless networks are susceptible to network attacks due to their inherentvulnerabilities. The radio signal used in wireless transmission canarbitrarily propagate through walls and windows; thus a wireless networkperimeter is not exactly known. This leads them to be more vulnerable toattacks such as eavesdropping, message interception and modifications comparedto wired-line networks. Security services have been used as countermeasures toprevent such attacks, but they are used at the expense of resources that arescarce especially, where wireless devices have a very limited power budget.Hence, there is a need to provide security services that are energy efficient.In this dissertation, we propose an energy efficient security framework. Theframework aims at providing security services that take into account energyconsumption. We suggest three approaches to reduce the energy consumption ofsecurity protocols: replacement of standard security protocol primitives thatconsume high energy while maintaining the same security level, modification ofstandard security protocols appropriately, and a totally new design ofsecurity protocol where energy efficiency is the main focus. From ourobservation and study, we hypothesize that a higher level of energy savings isachievable if security services are provided in an adjustable manner. Wepropose an example tunable security or TuneSec system, which allows areasonably fine-grained security tuning to provide security services at thewireless link level in an adjustable manner.We apply the framework to several standard security protocols in wirelesslocal area networks and also evaluate their energy consumption performance.The first and second methods show improvements of up to 70% and 57% inenergy consumption compared to plain standard security protocols,respectively. The standard protocols can only offer fixed-level securityservices, and the methods applied do not change the security level. The thirdmethod shows further improvement compared to fixed-level security by reducing(about 6% to 40%) the energy consumed. This amount of energy saving can bevaried depending on the configuration and security requirements
Using secure coprocessors to enforce network access policies in enterprise and ad hoc networks
Nowadays, network security is critically important. Enterprises rely on networks to improvetheir business. However, network security breaches may cause them loss of millions of dollars.Ad hoc networks, which enable computers to communicate wirelessly without the need forinfrastructure support, have been attracting more and more interests. However, they cannotbe deployed effectively due to security concerns.Studies have shown that the major network security threat is insiders (malicious orcompromised nodes). Enterprises have traditionally employed network security solutions(e.g., firewalls, intrusion detection systems, anti-virus software) and network access controltechnologies (e.g., 802.1x, IPsec/IKE) to protect their networks. However, these approachesdo not prevent malicious or compromised nodes from accessing the network. Many attacksagainst ad hoc networks, including routing, forwarding, and leader-election attacks, requiremalicious nodes joining the attacked network too.This dissertation presents a novel solution to protect both enterprise and ad hoc networksby addressing the above problem. It is a hardware-based solution that protects a networkthrough the attesting of a node's configuration before authorizing the node's access to thenetwork. Attestation is the unforgeable disclosure of a node's configuration to another node,signed by a secure coprocessor known as a Trusted Platform Module (TPM).This dissertation makes following contributions. First, several techniques at operatingsystem level (i.e., TCB prelogging, secure association root tripping, and sealing-free attestation confinement) are developed to support attestation and policy enforcement. Second, two secure attestation protocols at network level (i.e., Bound Keyed Attestation (BKA) andBatched Bound Keyed Attestation (BBKA)) are designed to overcome the risk of a man-inthe-middle (MITM) attack. Third, the above techniques are applied in enterprise networks todifferent network access control technologies to enhance enterprise network security. Fourth,AdHocSec, a novel network security solution for ad hoc networks, is proposed and evaluated. AdHocSec inserts a security layer between the network and data link layer of the networkstack. Several algorithms are designed to facilitate node's attestation in ad hoc networks,including distributed attestation (DA), and attested merger (AM) algorithm
Security technologies for wireless access to local area networks
In today’s world, computers and networks are connected to all life aspects and professions.
The amount of information, personal and organizational, spread over the network
is increasing exponentially. Simultaneously, malicious attacks are being developed at the
same speed, which makes having a secure network system a crucial factor on every level
and in any organization. Achieving a high protection level has been the goal of many
organizations, such as the Wi-Fi Alliance
R , and many standards and protocols have been
developed over time.
This work addresses the historical development of WLAN security technologies, starting
from the oldest standard, WEP, and reaching the newly released standard WPA3, passing
through the several versions in between,WPA, WPS, WPA2, and EAP. Along with WPA3,
this work addresses two newer certificates, Enhanced OpenTM and Easy ConnectTM. Furthermore,
a comparative analysis of the previous standards is also presented, detailing
their security mechanisms, flaws, attacks, and the measures they have adopted to prevent
these attacks. Focusing on the new released WPA3, this work presents a deep study
on both WPA3 and EAP-pwd. The development of WPA3 had the objective of providing
strong protection, even if the network’s password is considered weak. However, this
objective was not fully accomplished and some recent research work discovered design
flaws in this new standard.
Along with the above studies, this master thesis’ work builds also a network for penetration
testing using a set of new devices that support the new standard. A group of possible
attacks onWi-Fi latest security standards was implemented on the network, testing the response
against each of them, discussing the reason behind the success or the failure of the
attack, and providing a set of countermeasures applicable against these attacks. Obtained results show that WPA3 has overcome many of WPA2’s issues, however, it is still unable to overcome some major Wi-Fi vulnerabilities.No mundo de hoje, os computadores e as redes estão conectados praticamente a todos
os aspectos da nossa vida pessoal e profissional. A quantidade de informações, pessoais
e organizacionais, espalhadas pela rede está a aumentar exponencialmente. Simultaneamente,
também os ataques maliciosos estão a aumentar à mesma velocidade, o que faz
com que um sistema de rede seguro seja um fator crucial a todos os níveis e em qualquer
organização. Alcançar altos níveis de proteção tem sido o objetivo de trabalho de muitas
organizações, como a Wi-Fi Alliance
R , tendo muitos standards e protocolos sido desenvolvidos
ao longo do tempo.
Este trabalho aborda o desenvolvimento histórico das tecnologias de segurança para WLANs,
começando pelo standard mais antigo, WEP, e acabando no recém-chegado WPA3, passando
pelas várias versões intermedias, WPA, WPS, WPA2 e EAP. Juntamente com o
WPA3, este trabalho aborda os dois certificados mais recentes, Enhanced OpenTM e Easy
ConnectTM. Além disso, também é apresentada uma análise comparativa dos standards
anteriores, detalhando os seus principais mecanismos de segurança, falhas, ataques a que
são susceptíveis e medidas adotadas para evitar esses ataques. Quanto ao novo WPA3
e EAP-pwd, este trabalho apresenta um estudo aprofundado sobre os seus modos "Personal"
e "Enterprise". O desenvolvimento do WPA3 teve por objetivo fornecer proteção
forte, mesmo que a password de rede seja considerada fraca. No entanto, esse objetivo
não foi totalmente alcançado e alguma investigação realizada recentemente detectou falhas
de desenho nesse novo padrão.
Juntamente com os estudo dos standards acima referidos, o trabalho realizado para esta
tese de mestrado também constrói uma rede para testes de penetração usando um conjunto
de novos dispositivos que já suportam o novo standard. São aplicados vários ataques aos
mais recentes padrões de segurança Wi-Fi, é testada a sua resposta contra cada um deles,
é discutindo o motivo que justifica o sucesso ou a falha do ataque, e são indicadas
contramedidas aplicáveis a esses ataques. Os resultados obtidos mostram que o WPA3
superou muitos dos problemas do WPA2 mas que, no entanto, ainda é incapaz de superar
algumas das vulnerabilidades presentes nas redes Wi-Fi.First, I would like to express my deepest appreciation to those who gave me the possibility
to complete my study and get my Master degree, the Aga Khan Foundation, who has
supported me financiall
Secure and Privacy-Preserving Authentication Protocols for Wireless Mesh Networks
Wireless mesh networks (WMNs) have emerged as a promising concept to meet the
challenges in next-generation wireless networks such as providing flexible,
adaptive, and reconfigurable architecture while offering cost-effective
solutions to service providers. As WMNs become an increasingly popular
replacement technology for last-mile connectivity to the home networking,
community and neighborhood networking, it is imperative to design efficient and
secure communication protocols for these networks. However, several
vulnerabilities exist in currently existing protocols for WMNs. These security
loopholes can be exploited by potential attackers to launch attack on WMNs. The
absence of a central point of administration makes securing WMNs even more
challenging. The broadcast nature of transmission and the dependency on the
intermediate nodes for multi-hop communications lead to several security
vulnerabilities in WMNs. The attacks can be external as well as internal in
nature. External attacks are launched by intruders who are not authorized users
of the network. For example, an intruding node may eavesdrop on the packets and
replay those packets at a later point of time to gain access to the network
resources. On the other hand, the internal attacks are launched by the nodes
that are part of the WMN. On example of such attack is an intermediate node
dropping packets which it was supposed to forward. This chapter presents a
comprehensive discussion on the current authentication and privacy protection
schemes for WMN. In addition, it proposes a novel security protocol for node
authentication and message confidentiality and an anonymization scheme for
privacy protection of users in WMNs.Comment: 32 pages, 10 figures. The work is an extended version of the author's
previous works submitted in CoRR: arXiv:1107.5538v1 and arXiv:1102.1226v
Firewall Traversal in Mobile IPv6 Networks
Middleboxes, wie zum Beispiel Firewalls, sind ein wichtiger Aspekt für eine Großzahl moderner IP-Netzwerke. Heute IP-Netzwerke basieren überwiegend auf IPv4 Technologien, daher sind viele Firewalls und Network Address Translators (NATs) ursprünglich für diese Netzwerke entwickelt worden. Die Entwicklung von IPv6 Netzwerken findet zur Zeit statt. Da Mobile IPv6 ein relativ neuer Standard ist, unterstützen die meisten Firewalls die für IPv6 Netzwerke verfügbar sind, noch kein Mobile IPv6. Sofern Firewalls sich nicht der Details des Mobile IPv6 Protokolls bewusst sind, werden sie entweder Mobile IPv6 Kommunikation blockieren oder diesen sorgfältig handhaben. Dieses stellt einen der Haupthinderunggründe zum erfolgreichen Einsatz von Mobile IPv6 da.Diese Arbeit beschreibt die Probleme und Auswirkungen des Vorhandenseins von Middleboxes in Mobile IPv6 Umgebungen. Dazu wird zuerst erklärt welche Arten von Middleboxes es gibt, was genau eine Middlebox ist und wie eine solche Middlebox arbeiten und zweitens die Probleme identifiziert und die Auswirkungen des Vorhandenseins von Firewalls in Mobile IPv6 Umgebungen erklärt. Anschließend werden einige State-of-the-Art Middlebox Traversal Ansätze untersucht, die als mögliche Lösungen um die Mobile IPv6 Firewall Traversal Probleme zu bewältigen betrachtet werden können. Es wird detailiert erklärt wie diese Lösungen arbeiten und ihre Anwendbarkeit für Mobile IPv6 Firewall Traversal evaluiert.Als Hauptbeitrag bringt diese Arbeit zwei detailierte Lösungsansätze ein, welche das Mobile IPv6 Firewall Traversal Problem bewältigen können. Der erste Lösungsansatz, der NSIS basierte Mobile IPv6 Firewall Traversal, basiert auf dem Next Steps in Signaling (NSIS) Rahmenwerk und dem NAT/Firewall NSIS Signaling Layer Protocol (NAT/FW NSLP). Anschließend wird der zweite Lösungsansatz vorgestellt, der Mobile IPv6 Application Layer Gateway. Diese Arbeit erklärt detailiert, wie diese Lösungsansätze die Probleme und Auswirkungen des Vorhandenseins von Middleboxes in Mobile IPv6 Umgebungen bewältigen. Desweitern stellt diese Arbeit vor, wie die NSIS basierte Mobile IPv6 Firewall Traversal und die Mobile IPv6 Application Layer Gateway Proof-of-Concept Implementierungen, die im Rahmen dieser Arbeit entwicklet wurden, implementiert wurden. Abschließend werden die Proof-of-Concept Implementierungen sowie die beiden Lösungsansätze allgemein evaluiert und analysiert
Internet Authentication for Remote Access
It is expected that future IP devices will employ a variety of
different network access technologies to gain ubiquitous
connectivity. Currently there are no authentication protocols
available that are lightweight, can be carried over arbitrary
access networks, and are flexible enough to be re-used in the
many different contexts that are likely to arise in future
Internet remote access. Furthermore, existing access procedures
need to be enhanced to offer protection against
Denial-of-Service (DoS) attacks, and do not provide
non-repudiation. In addition to being limited to specific
access media, some of these protocols are limited to specific
network topologies and are not scalable.
This thesis reviews the authentication infrastructure
challenges for future Internet remote access supporting
ubiquitous client mobility, and proposes a series of solutions
obtained by adapting and reinforcing security techniques
arising from a variety of different sources. The focus is on
entity authentication protocols that can be carried both by the
IETF PANA authentication carrier and by the EAP mechanisms, and
possibly making use of an AAA infrastructure. The core idea is
to adapt authentication protocols arising from the mobile
telecommunications sphere to Internet remote access. A proposal
is also given for Internet access using a public key based
authentication protocol. The subsequent security analysis of
the proposed authentication protocols covers a variety of
aspects, including: key freshness, DoS-resistance, and
"false-entity-in-the-middle" attacks, in addition to identity
privacy of users accessing the Internet via mobile devices.
This work aims primarily at contributing to ongoing research on
the authentication infrastructure for the Internet remote
access environment, and at reviewing and adapting
authentication solutions implemented in other spheres, for
instance in mobile telecommunications systems, for use in
Internet remote access networks supporting ubiquitous mobilit
Nonce-based Kerberos is a Secure Delegated AKE Protocol
Kerberos is one of the most important cryptographic protocols, first because it is the basisc authentication protocol in Microsoft\u27s Active Directory and shipped with every major operating system, and second because it served as a model for all Single-Sign-On protocols (e.g. SAML, OpenID, MS Cardspace, OpenID Connect). Its security has been confirmed with several Dolev-Yao style proofs, and attacks on certain versions of the protocol have been described.
However despite its importance, despite its longevity, and despite the wealth of Dolev-Yao-style security proofs, no reduction based security proof has been published until now. This has two reasons: (1) All widely accepted formal models either deal with two-party protocols, or group key agreement protocols (where all entities have the same role), but not with 3-party protocols where each party has a different role. (2) Kerberos uses timestamps and nonces, and formal security models for timestamps are not well understood up to now.
As a step towards a full security proof of Kerberos, we target problem (1) here: We propose a variant of the Kerberos protocol, where nonces are used instead of timestamps. This requires one additional protocol message, but enables a proof in the standard Bellare-Rogaway (BR) model. The key setup and the roles of the different parties are identical to the original Kerberos protocol.
For our proof, we only require that the authenticated encryption and the message authentication code (MAC) schemes are secure. Under these assumptions we show that the probability that a client or server process oracle accepts maliciously, and the advantage of an adversary trying to distinguish a real Kerberos session key from a random value, are both negligible.
One main idea in the proof is to model the Kerberos server a a public oracle, so that we do not have to consider the security of the connection client--Kerberos. This idea is only applicable to the communication pattern adapted by Kerberos, and not to other 3-party patterns (e.g. EAP protocols)
Trust and integrity in distributed systems
In the last decades, we have witnessed an exploding growth of the Internet. The massive adoption of distributed systems on the Internet allows users to offload their computing intensive work to remote servers, e.g. cloud. In this context, distributed systems are pervasively used in a number of difference scenarios, such as web-based services that receive and process data, cloud nodes where company data and processes are executed, and softwarised networks that process packets. In these systems, all the computing entities need to trust each other and co-operate in order to work properly.
While the communication channels can be well protected by protocols like TLS or IPsec, the problem lies in the expected behaviour of the remote computing platforms, because they are not under the direct control of end users and do not offer any guarantee that they will behave as agreed. For example, the remote party may use non-legitimate services for its own convenience (e.g. illegally storing received data and routed packets), or the remote system may misbehave due to an attack (e.g. changing deployed services). This is especially important because most of these computing entities need to expose interfaces towards the Internet, which makes them easier to be attacked. Hence, software-based security solutions alone are insufficient to deal with the current scenario of distributed systems. They must be coupled with stronger means such as hardware-assisted protection.
In order to allow the nodes in distributed system to trust each other, their integrity must be presented and assessed to predict their behaviour. The remote attestation technique of trusted computing was proposed to specifically deal with the integrity issue of remote entities, e.g. whether the platform is compromised with bootkit attacks or cracked kernel and services. This technique relies on a hardware chip called Trusted Platform Module (TPM), which is available in most business class laptops, desktops and servers. The TPM plays as the hardware root of trust, which provides a special set of capabilities that allows a physical platform to present its integrity state.
With a TPM equipped in the motherboard, the remote attestation is the procedure that a physical node provides hardware-based proof of the software components loaded in this platform, which can be evaluated by other entities to conclude its integrity state. Thanks to the hardware TPM, the remote attestation procedure is resistant to software attacks. However, even though the availability of this chip is high, its actual usage is low.
The major reason is that trusted computing has very little flexibility, since its goal is to provide strong integrity guarantees. For instance, remote attestation result is positive if and only if the software components loaded in the platform are expected and loaded in a specific order, which limits its applicability in real-world scenarios. For such reasons, this technique is especially hard to be applied on software services running in application layer, that are loaded in random order and constantly updated. Because of this, current remote attestation techniques provide incomplete solution. They only focus on the boot phase of physical platforms but not on the services, not to mention the services running in virtual instances.
This work first proposes a new remote attestation framework with the capability of presenting and evaluating the integrity state not only of the boot phase of physical platforms but also of software services at load time, e.g. whether the software is legitimate or not. The framework allows users to know and understand the integrity state of the whole life cycle of the services they are interacting with, thus the users can make informed decision whether to send their data or trust the received results.
Second, based on the remote attestation framework this thesis proposes a method to bind the identity of secure channel endpoint to a specific physical platform and its integrity state. Secure channels are extensively adopted in distributed systems to protect data transmitted from one platform to another. However, they do not convey any information about the integrity state of the platform or the service that generates and receives this data, which leaves ample space for various attacks. With the binding of the secure channel endpoint and the hardware TPM, users are protected from relay attacks (with hardware-based identity) and malicious or cracked platform and software (with remote attestation).
Third, with the help of the remote attestation framework, this thesis introduces a new method to include the integrity state of software services running in virtual containers in the evidence generated by the hardware TPM. This solution is especially important for softwarised network environments. Softwarised network was proposed to provide dynamic and flexible network deployment which is an ever complex task nowadays. Its main idea is to switch hardware appliances to softwarised network functions running inside virtual instances, that are full-fledged computational systems and accessible from the Internet, thus their integrity is at stake. Unfortunately, currently remote attestation work is not able to provide hardware-based integrity evidence for software services running inside virtual instances, because the direct link between the internal of virtual instances and hardware root of trust is missing. With the solution proposed in this thesis, the integrity state of the softwarised network functions running in virtual containers can be presented and evaluated with hardware-based evidence, implying the integrity of the whole softwarised network.
The proposed remote attestation framework, trusted channel and trusted softwarised network are implemented in separate working prototypes. Their performance was evaluated and proved to be excellent, allowing them to be applied in real-world scenarios. Moreover, the implementation also exposes various APIs to simplify future integration with different management platforms, such as OpenStack and OpenMANO
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