Transcript Chapter 1: Introduction

Network-layer Security of Mobile Ad
hoc Networks
Jiangyi Hu
Advisor: Dr. Mike Burmester
Outline
Introduction
Secure routing
Existing routing protocols
Routing attacks
Secure routing protocols
Cooperation enforcement
Solutions to enforce cooperation
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Introduction
Example of Mobile Ad hoc networks
C
F
B
A
D
E
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Introduction
Characteristics of Manet:
Wireless connection, broadcasting
Dynamic topology
Unfriendly environment
Limited resource
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Introduction
Advantage
Ease of deployment
Fast to deploy
Decreased dependence on infrastructure
Application of Manet
emergency deployments
search and rescue missions
military operations
commercial applications
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Introduction
Vulnerabilities
The basic mechanism
The security mechanism
Security goals
Availability
Confidentiality
Integrity
Authentication
Non-repudiation
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Secure routing
Existing routing protocols
Security threats for routing
Secure routing protocols
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Existing routing protocols
Table driven routing
DSDV (destination sequenced distance vector)
CGSR (Clusterhead Gateway Switch Routing)
WRP (Wireless Routing Protocol)
On demand routing
DSR (dynamic source routing)
AODV (ad-hoc on-demand distance vector)
TORA (Temporally Ordered Routing Algorithm)
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DSR
Dynamic source routing
Route discovery/Route maintenance
Every packet have the entire route
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DSR
A
S-A-B-D
S-A-B-D
B
S-A-B-D
S-A
S
S
D
S-A-B
S-C-E-H
S-A-B
S-C-E
H
E
S
S-C-E
S-C
C
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S-C-E
S-C-E-H
S-C-E-F
F
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AODV
Ad-hoc on-demand distance vector routing
No maintenance of routing table as in DSDV
Each node remembers only the next hop for
the route, not the whole route
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AODV
D
C
B
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A
E
S
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: Reverse path
: Forward path
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Routing attacks
Classification:
External attack vs. Internal attack
Passive attack vs. Active attack
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Routing attacks
Attacks for routing:
Modification
Fabrication
Wormhole attack (tunneling)
Denial of service attack
Invisible node attack
The Sybil attack
Rushing attack
Non-cooperation
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Modification
Modify the protocol fields of control messages
Compromise the integrity of routing
computation
Cause network traffic to be dropped,
redirected to a different destination or take a
longer route
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Fabrication
Generating false routing messages, e.g.
routing error messages
Can cause denial-of-service
S
B
M
C
D
: Connected
: Connected through multi-hops
: Forward false error message
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Wormhole attack
Colluding attackers uses “tunnels” between
them to forward packets
Place the attacker in a very powerful
position
The attackers take control of the route by
claiming a shorter path
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Wormhole attack
Example of wormhole attack
tunnel
N
M
D
C
S
B
A
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Denial of service attack
Adversary floods irrelevant data
Consume network bandwidth
Consume resource of a particular node
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Invisible node attack
Attack on DSR
Malicious does not append its IP address
M becomes “invisible” on the path
S
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M
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The Sybil attack
Represents multiple identities
Disrupt geographic and multi-path routing
B
M1
M5
M2
M3
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M4
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Rushing attack
Directed against on-demand routing protocols
The attacker hurries route request packet to
the next node to increase the probability of
being included in a route
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Non-cooperation
Node lack of cooperation, not participate in
routing or packet forwarding
Node selfishness, save energy for itself
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Secure routing protocols
SRP (Secure Routing Protocol)
ARAN (Authenticated Routing for Ad hoc
Networks)
Ariadne
SEAD (Secure Efficient Ad hoc Distance
vector routing )
Cope with wormhole attack
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SRP
Assume a shared secret key between the
source node and the destination node
Verification of the route request/reply packet
using MAC (Message Authentication Code)
Identities of intermediate nodes accumulated
in the route request packet
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ARAN
Requires a trusted certification authority
Every node forwards a route request or a
route reply must verify it and sign it
Asymmetric cryptography is costly in terms of
CPU and energy usage
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ARAN
Example of ARAN:
S
[RDP,IPD, CertS, NS, t]KS- , CertS
[[REP,IPS , CertD , NS , t]KD-, CertD ]KB- , CertB
B
[[RDP,IPD, CertS, NS, t]KS- , CertS ] KB- , CertB
C
[[REP,IPS , CertD , NS , t]KD-, CertD ]KC- , CertC
[[RDP,IPD, CertS, NS, t]KS- , CertS ] KC- , CertC
[REP,IPS , CertD , NS , t]KD-, CertD
: broadcast
: unicast
D
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Ariadne
Each node generates a one-way key chain
(K0,K1,…Ki,…Kn) and publishes the keys in reverse
order from generation
The sender picks Ki which will still be secret at the time
the receiver receives the packet
When a receiver receives a packet, it first verifies Ki is
still secret, then it buffers the packet and waits for the
sender to publish key Ki
Need time synchronization
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SEAD
Based on Destination-Sequence Distance
Vector Protocol (DSDV)
Uses one-way hash chain (h0 ,h1,…hi,…hn )
Use a hash value corresponding to the
sequence number and metric in a routing
update
Attacker can never forge better sequence
number or better metric
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Cope with wormhole attack
Geographic leash
Ensures that the recipient of the packet is within a
certain distance from the sender
Temporal leash
Ensures that the packet has an upper bound on its
lifetime
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Cooperation enforcement
Introduction
Solutions
Currency based
Local monitoring
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Cooperation enforcement
Currency based
Nuglets
Sprite
Local monitoring
Watchdog and path rater
Confidant
CORE
Token-based
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Nuglets
Nuglets ---- a virtual currency
Packet purse model
Sender pay nuglets in advance
Intermediate node takes nuglets for forwarding
service
Packet trade mode
Intermediate nodes “buys” the packet from the
previous one and “sells” it to the next one
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Nuglets
Advantage
Packet
purse
model
deters nodes from
difficult to estimate the
sending useless data and number of nuglets that
overloading the network
are required
source does not have to
Packet
trade mode know in advance the
number of nuglets
required
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Disadvantage
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can not prevent nodes
from overloading the
network
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Sprite
Uses credit to provide incentive to selfish
nodes
Nodes keep receipt to get payments from the
Credit Clearance Service (CCS)
Credit that a node receives depends on
whether its forwarding is successful or not
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Watchdog and path rater
A node's watchdog Listens promiscuously to the
next node's transmissions
If a node does not forward, it is misbehaving
The path rater choose the best path from watchdog
ratings
S
A
B
C
D
: Connected
: Connected through multi-hops
: Forwarding
: Listening
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Confidant
Consists of:
Monitor
Reputation System
Path Manager
Trust Manager
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Confidant
Detects malicious nodes
by means of observation or reports about several
types of attacks
Allows nodes
to route around misbehaved nodes
to isolate misbehaved nodes from the network
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CORE
Basic components:
Reputation table
stored in each node
the reputation value of each node
Watchdog mechanism
detect misbehavior nodes
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Token-based
Each node has to have a token
Local neighbors monitor
The token is renewed via multiple neighbors
The period of validity of a node’s token is
dependent on how long it has stayed and how
well it has behaved
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Token-based
Composed of:
Neighbor verification
Neighbor monitoring
Intrusion reaction
Security enhanced routing protocol
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Summary
Introduction
Secure routing
Existing routing protocols
Security attacks
Defenses
Node cooperation
Currency based
Local monitoring
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Thank you!