kais t security architecture in a multi-hop mesh network conference in france, 2006 2006. 9. 26....
TRANSCRIPT
KAIST
Security architecture in a multi-hop Security architecture in a multi-hop
mesh networkmesh network
Conference in France, 2006
2006. 9. 26.
Presented by JooBeom Yun
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ContentsContents
Introduction
Problematic
State of the art and related worksAd-hoc network security
Users’ access to wireless networks
Proposed security architecturePANA framework
Technical description
Security analysis of the solution
Future works
Conclusions
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Introduction Introduction
Multi-hop mesh network
Extension of a wireless mesh network by an ad hoc network
Authentication mechanism
is essential
In wireless network and
in an ad hoc network
The biggest problem
Authentication of the mobile node
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ProblematicProblematic
Multi-hop mesh network inherits from the security problems
Ad-hoc networks
Passive eavesdropping, message replaying, message distorsion, active impersonation
DoS
Mesh network (Fake APs)
Eavesdropping, tampering, DoS
Access control enforced by operators
Authentication, authorization
Protect data exchanges
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State of the art and related worksState of the art and related works
Ad-hoc network security
Covers secure routing, key establishment, authentication, certification/revocation services
Secure routing
designed security protocols - ARAN[1], Ariadne[2], SAODV[3]
Certification and revocation services
Threshold cryptography[5,6], ID-based cryptography[7], both cryptography[8]
Users’ access to wireless networks
IEEE 802.1X standard
EAP(Extensible Authentication Protocol) messages between the user and the AP
PANA(Protocol for Carrying Authentication and Network Access) protocol
Medium independent solution
EAP messages to be carried over IP
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Proposed security architectureProposed security architecture
IEEE 802.1XMobiles may be authenticated by the mesh AR
Authentication is done at layer 2 (MAC address)
The mobile is assumed to be directly attached to the mesh routers
PANAAuthenticate using the IP protocol
EAP lower-layer
Any EAP method is suitable for authentication
PANA framework
Technical description
Security analysis of the solution
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PANA frameworkPANA framework
PANA Client (PaC)Request authentication, provide the credentials
PANA Authentication Agent (PAA)Interacts with the AS to determine the access control state and communicates EP
Enforcement Point (EP)Controls access of a new node to the network
Authentication Server (AS)Verify the credentials of a node requiring access to the network
Asked by the PAA
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Technical description (1/3)Technical description (1/3)
Configuration (e.g. DHCPv4)
PANA Discovery phase and begin of Authentication and authorization phase
Authorization [IKE-PSK, PaC-DI,
Session-id]
PANA-Bind-Request / PANA-Bind-Answer
IKE
SA
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Technical description (2/3)Technical description (2/3)
Encapsulation of EAP packets during PANA authentication
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Technical description (3/3)Technical description (3/3)
EAP-MD5Login/password
Known vulnerabilities (dictionary and brute-force attacks)
Does not support mutual authentication
EAP-TLSSecure and robust against attacks
Mutual authentication
Protect network access by providing an IKE-PSK
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PANA/EAP-TLS authentication procedure (1/2)PANA/EAP-TLS authentication procedure (1/2)
PANA-Auth-Request (EAP-Request/Identity)
PANA-Auth-Answer (EAP-Response/ Identity (MyID)) Access-Request (EAP-Response/ Identity (MyID))
Access-Challenge(EAP-Request/EAP-Type=EAP-TLS(TLS Start))PANA-Auth-Request(EAP-Request/EAP-Type=EAP-TLS(TLS Start))
PANA-Auth-Answer(EAP-Response/EAP-Type=EAP-TLS(TLS
Client-hello))
Access-Request(EAP-Response/EAP-Type=EAP-TLS(TLS
Client-hello))
Access-Challenge(EAP-Request/EAP-Type=EAP-TLS(TLS
Server_hello, TLS certificate, [TLS server_key_exchange,][TLS
Certificate_request,] TLS server_hello_done))
PANA-Auth-Request(EAP-Request/EAP-Type=EAP-TLS(TLS
Server_hello, TLS certificate, [TLS server_key_exchange,][TLS
Certificate_request,] TLS server_hello_done))
① ②
③
④
⑤
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PANA/EAP-TLS authentication procedure (2/2)PANA/EAP-TLS authentication procedure (2/2)
PANA-Auth-Answer (EAP-Response/ EAP-Type=EAP-TLS (TLS
Certificate, TLS client_key_exchange, [TLS certificate_verify,] TLS
Change_cipher_spec, TLS finished))
Access-Request (EAP-Response/ EAP-Type=EAP-TLS (TLS
Certificate, TLS client_key_exchange, [TLS certificate_verify,] TLS
Change_cipher_spec, TLS finished))
PANA-Auth-Answer (EAP-Response/ EAP-Type=EAP-TLS) EAP-Response/ EAP-Type=EAP-TLS
Access-Challenge(EAP-Request/EAP-Type=EAP-TLS(TLS
Change_cipher_spec, TLS finished))
Access-Accept(EAP-Success)PANA-Bind-Request (EAP-Success,Device-Id,[protection-Cap],MAC)
PANA-Auth-Request(EAP-Request/EAP-Type=EAP-TLS(TLS
Change_cipher_spec, TLS finished))
PANA-Bind-Answer (Device-Id,[protection-Cap],MAC)
⑥
⑦
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IPsec/IKE protectionIPsec/IKE protection
Multi-hop environmentAccess control need to operate at the network layer or upper layers
IPsec protocol suite
Support strong access control to authenticate packets’ origin
Provide data encryption (using ESP)
In order to setup an IPsec securityinitiate IKE exchanges
authenticate to each other.
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Security analysis of the solution (1/2)Security analysis of the solution (1/2)
Protection against replay attacks
Spoofing messages
Sequence numbers are randomly initialized at the beginning of the session
Protection against PaC DoS attacks
Spoofed message
MAC protection
Providing message integrity
Service theft attack
provides message integrity and protects the PaC’s identifier.
Spoofing PAA message
An attacker can spoof PAA messages
Less secure authentication method
negotiate parameters after the establishment of PANA security association
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Security analysis of the solution (2/2)Security analysis of the solution (2/2)
PAA DoS attackOverload the PAA with PANA-PAA-Discover messages
Add a cookie (Device ID) to the PANA-Start-Request message
DHCP DoS attackDoS attacks are possible by depleting the IP address space
Other possible attacksAd-hoc and mesh networks
vulnerable to passive eavesdropping, message replaying, message distorsion, easy man-in-the-middle, active impersonation, DoS, IP spoofing
Cryptographic technics(IPsec) – prevent eavesdropping, message distorsion, active impersonation
Mesh networksWorst DoS is not possible (using access control)
Access control, cryptographic technics
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Future worksFuture works
The proposed architecturecombines PANA with EAP-TLS in a multi-hop mesh network.
EAP-TLSMutual authentication and strong robustness against attacks
Heavy treatment (the use of asymmetric cryptography)
Need PKI
EAP-MD5Simpler
Vulnerable to eavesdropping attacks
Workingcombine the simplicity of EAP-MD5 and the robustness of EAP-TLS
PANA exposes to IP address starvation in IPv4.Adapting IEEE 802.1X to multi-hop mesh networks (new research direction)
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ConclusionsConclusions
Access network security in a multi-hop mesh networkaccess control
data protection
IEEE 802.1X standardcan be extended to support authentication in multi-hop mesh networks
It’s not easy (modify the standard)
A combination of EAP-TLS over PANA and IPsec has been proposed.
PANA is relying on the availability of IP addresses.IPv6
Temporary private addresses
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Q & AQ & A