Transcript A Survey of Secure Wireless Ad Hoc Routing

A Survey of Secure
Wireless Ad Hoc Routing
Article by: YIH-CHUN HU, ADRIAN PERRIG
IEEE Security and Privacy special issue on Making Wireless Work, 2(3):28-39, 2004.
Presented by: Devendra Salvi
04-17-2007
Multihop Ad Hoc network
Access Point
Ad Hoc N/W
Network boundary
Outline
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Attacks on Ad hoc networks
Key setup in Ad hoc networks
SEAD in mobile wireless Ad Hoc network
A secure on-demand routing protocol for ad
hoc networks
Securing AODV
Review
Questions
Attacks on Ad hoc networks
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Attacks on ad hoc network routing protocols
are mainly
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Routing disruption attack
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Wherein the attacker causes legitimate data packets to be
routed in dysfunctional ways.
Resource consumption attack
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Wherein the attacker injects packets into the network to
consume network resources such as bandwidth or to consume
node resources such as memory/computational power.
Attacks on ad hoc network routing
protocols
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Routing disruption attack
Shortest
path
Drop packets
Blackhole /
Grayhole
Source
Destination
Insert forged
routing packets
Attacks on ad hoc network routing
protocols
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Wormhole
Records Traffic for
network A & replays it
in network B
Intruder Node X
Node A
Node B
Intruder Node X’
X’mission
range of B
X’mission
range of A
Attacks on ad hoc network routing
protocols
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Solution for wormhole attacks
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Packet Leashes is keeping constraints on packet
in either of two ways
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Temporal
 Temporal leashes rely on extremely precise time
synchronization and timestamps in each packet. A
packet’s travel time is approximated as the difference
between the receive time and the timestamp.
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Geographical
Attacks on ad hoc network routing
protocols
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Solution for wormhole attacks
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Packet Leashes is keeping constraints on packet
in either of two ways
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Temporal
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Geographical
 Where in location information and loosely synchronized
clocks is used to create a leash
 The distance between the sender and receiver is
calculated nodes velocity and timestamps.
Key setup in Ad hoc networks
To authenticate a legitimate node
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Establishing private keys
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Share private keys between each pair of nodes
before deployment.
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Pitfall: when new nodes join network later
Solution:
1. Establishing trust and keys between two nodes
in an ad hoc network; Master-slave nodes.
Key setup in Ad hoc networks
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SUCV addresses (statistically unique
cryptographically verifiable)
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Each node generates a public- and private-key pair, and
then chooses its address based on a cryptographic hash
function of the public key
E.g. 1. A node’s entire IPv6 address is the hash
function’s output
Key setup in Ad hoc networks
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Certificates from a certificate authority
node address, node public key,
and a signature from the CA (s).
Key setup in Ad hoc networks
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Transitive trust and PGP trust graphs
node address, node public key,
and a signature from the CA.
Node B
Node A
Node C
SEAD in mobile wireless Ad Hoc network
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To support use of SEAD with nodes of limited
CPU processing capability, and to guard
against DoS attacks in which an attacker
attempts to cause other nodes to consume
excess network bandwidth or processing
time, efficient one-way hash functions are
used while asymmetric cryptographic
operations in the protocol are not used.
SEAD: Secure efficient Ad hoc Distance vector routing protocol.
SEAD in mobile wireless Ad Hoc network
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Destination-Sequenced Distance-Vector ad
hoc network routing protocol (DSDV).
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Distance vector routing; each router maintains list of all
possible destinations within the network.
Each node router entry maintains:
1. address of destination (identity)
2. Nodes which form shortest known distance
to destination (metric) usually # of hops.
3. address of nodes neighbor which is the first
hop on the shortest route to destination
SEAD in mobile wireless Ad Hoc network
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Destination-Sequenced Distance-Vector ad
hoc network routing protocol (DSDV).
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DSDV introduces a sequence number in each routing
table entry.
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Prevents routing loops.
SEAD in mobile wireless Ad Hoc network
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Hash Chains
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A one-way hash chain is built on a one-way hash
function.
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To create a one-way hash chain, a node chooses a
random x ∈ {0,1}ρ and computes the list of values h0,
h1, h2, h3, ..., hn,where h0 = x, and hi = H(hi –1) for 0 < i
≤ n, for some n.
E.g. Given an authenticated hi value, a node can
authenticate hi–3 by computing H(H(H(hi –3))) and
verifying that the resulting value equals hi
A secure on-demand routing protocol for
ad hoc networks
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Ariadne is a secure on-demand routing protocol that withstands node
compromise and relies only on highly efficient symmetric cryptography.
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Ariadne discovers routes on-demand (as they are needed) through route discovery and uses
them to source route data packets to their destinations.
*Message authentication code (MAC) computed with key KSD over unique data—
for example, a timestamp
Securing AODV
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The Ad hoc On-demand Distance Vector
routing protocol (AODV) spreads distance
vector routing information in an on-demand
manner.
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There are two protocols to secure routing
protocols
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Authenticated routing for ad hoc networks (ARAN)
SAODV
Securing AODV
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Authenticated routing for ad hoc networks
(ARAN)
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Kimaya Sanzgiri and her colleagues developed authenticated routing for ad hoc
networks (ARAN), which is based on AODV.
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In ARAN, each node has a certificate signed by a trusted authority, which
associates its IP address with a public key.
Securing AODV
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(ARAN)
1. To initiate a route discovery, the initiator S broadcasts a signed ROUTE REQUEST
packet that includes the target D, its certificate (certS), a nonce N, and a timestamp t.
2. Each node that forwards this REQUEST checks the signature or signatures. Node C
checks node B’s certificate certB, then checks the signature on the outer message. C then
verifies the certificate certS for initiator S and uses the key in the certificate to verify the
signature on the REQUEST.
3. If the signatures are valid, the forwarding node removes the last forwarder’s signature
and certificate, signs the original REQUEST, and includes its own certificate. The node
then broadcasts the REQUEST. Node C removes node B’s signature, signs the resulting
REQUEST, and includes its own certificate. Node C then broadcasts the REQUEST.
4. When the first ROUTE REQUEST from a route discovery reaches the target, the target
signs a ROUTE REPLY and sends it to the node from which it received the REQUEST. the
target D returns a signed ROUTE REPLY to the previous hop C
Securing AODV
SAODV:
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A signature is used to authenticate most fields of a route
request and route reply and hash chains are used to
authenticate the hop count.
•A node first authenticates the RREQ to
ensure that each field is valid.
•It then performs duplicate suppression to
ensure that it forwards only a single RREQ
for each route discovery.
•The node then increments the hop-count
field in the RREQ header, hashes the hop
count authenticator, and rebroadcasts the
RREQ, together with its RREQ-SSE
extension.
Review
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Strengths
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Comprehensive study of security protocols on
wireless ad hoc networks
Review
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Weaknesses
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Authors do not present any evaluations of the
protocol.
Improvements
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Implementation of the discussed protocols.
Questions ?