A Security protocol for Mobile Ad-hoc
Networks
Thesis Report
Student:
Lijun Jia
advisor: Dr. Mangir
05/18/2007
A Security protocol for Mobile Ad-hoc networks
Outline
•
•
•
•
•
•
•
•
•
•
•
Background
Problem Statement
Objective
Methods Used
Research Methodology
Root causes of key Attacks against ad hoc network
Defining Security Requirements
Secure AODV (SAODV) Design
Secure AODV (SAODV) Operation
Performance Analysis of Secure AODV
Effect of Malicious Node Behavior
A Security protocol for Mobile Ad-hoc networks
Background
Features of Ad hoc networks:
•
no fixed network infrastructure
•
deployed as multi hop packet networks rapidly
•
with relatively low expense
Such networks can be very useful in scenarios where natural conditions or time
constraints make it impossible to pre-deploy infrastructure. Meanwhile, secure
routing has become an excellent topic of open research because of the
extraordinary gap between the nature of ad hoc network and the security required
by its applications.
A Security protocol for Mobile Ad-hoc networks
Problem Statement
•
Most current ad hoc network research has focused on providing
routing services without considering security. Many ad hoc routing
protocols have been proposed, such as DSR,AODV,TORA, DSDV
and WRP, but none of the proposals have defined security
requirements. Therefore, normal ad hoc networks are easily attacked
by malicious actions. We classify following three malicious
behaviors against ad hoc routing protocols:
–
Modification Attacks
•
–
Malicious modification of fields in protocol control messages can cause
traffic redirection, and denial of service.
Impersonation Attacks
•
–
Masquerading as another node (identity spoofing)
Fabrication Attacks
•
Generation of false routing messages
A Security Protocol for Mobile Ad-hoc Networks
Objective
•
Identify the main issues for the attack action in ad hoc
protocols, especially for AODV.
•
Gain fundamental understanding of the effects on malicious
actions.
•
Find a robust solution to prevent attack actions in ad hoc
network.
A Security Protocol for Mobile Ad-hoc Networks
Approaches Used
•
•
•
•
•
•
Study the basic principal of ad hoc network
Review of the existing routing protocols.
Understand effects of key attacks against ad hoc network (External Attacks,
Internal Attacks).
Design security metrics/Design a set of related security components.
Extend the existing protocol using those components.
Security and network performance analysis.
•
Research Methodology
•
The case study approach was used as a research methodology to accomplish our
thesis.
–
–
•
Firstly, most of the relevant researches have been extensively studied.
Secondly, we assume 4 cases in our simulations, and use OPNET Modeler 12.0
simulator to compare and evaluate the performance efficiency for AODV with and
without security conditions based on following metrics.
Five performance metrics are computed for each simulation:
–
1) Packet Delivery Fraction, 2) Packet/Byte Overhead, 3) Average Route Latency, 4)
Average Path Length, and 5) Average End-to-End Delay of Data Packets:
Overview AODV
•
Definition
–
•
Ad hoc On-Demand Distance Vector (AODV) routing protocol is a reactive routing
protocol for MANET that maintains routes only between nodes that need to
communicate.
Features of AODV
–
–
–
•
Routing messages have small packets size.
Build routes with the shortest path.
Use source/destination sequence number (SN) to specify how fresh a route is
AODV Operation
–
Route Discovery
–
–
Route Setup
Route maintenance
AODV Route Establishment Process
Main Issues of Key Attacks against Ad Hoc Network (1)
1. Attacks using Modification:
•
•
Malicious modification of protocol messages
Examples :
–
–
–
Redirection with modified sequence numbers
Redirection with modified hop counts
Tunneling attacks (Wormhole attack )
Main issues of AODV for the modification attack action :
• In AODV protocol the main design issue is to achieve efficiency in ad hoc network
environment, but no way to verify the routing metrics included in protocol packets, no
message integrity. Therefore, an attacker can easily modify them and cause different
security problems in routing.
Main Issues of key Attacks against ad hoc network (2)
2. Attacks using Impersonation :
•
Masquerading as another node or Misrepresentation of identity by
altering MAC or IP address in outgoing packets
Examples :
•
–
Forming routing loops by spoofing
(a)
(b)
(c)
Main issues of AODV for the impersonation attack action :
•
In AODV protocol, there is no message authentication. Therefore, an attacker can
easily capture normal nodes, and then cause degradation in network
communications, unreachable nodes, and possible routing loops .
Main Issues of key Attacks against ad hoc network (3)
3. Attacks using Fabrication :
•
•
Generation of false routing messages
Examples :
–
Falsifying route error messages
Main issues of AODV for the fabrication attack action :
• In AODV protocol, there is no verification of message contents, and no nonrepudiation. Therefore, the malicious node may insulate any node quite easily.
Defining Security Requirements
•
•
Common Security Requirements:
–
No spoofing
–
–
–
–
–
No fabricated messages
No malicious alteration of routing messages
No routing loops
No route redirection
unauthorized nodes should be excluded from routing
Secure Ad Hoc Routing – Properties and Techniques used to
guarantee these properties:
Secure AODV (SAODV) Design (1)
•
Our Secure AODV Protocol Metrics:
–
Timeliness:
Routing updates need to be sent in a timely fashion. Timestamps and timeout
mechanisms can guarantee the freshness of the routes they provide.
–
Authentication:
ensures the identity of the party with which communications are exchanged,
before granting it access to the network.
–
Non-repudiation:
the originator of a message cannot deny having sent the message. If nonrepudiation is guaranteed, the receiver of a wrong message can prove that the
originator sent it, and that therefore the originator misbehaved.
•
Preliminary
–
There is a key management subsystem to make it possible for each node to
obtain public keys from the other nodes, called the trust third part.
–
SAODV is an extension of the AODV routing protocol
Secure AODV (SAODV) Design (2)
• AODV Vs SAODV for Message Format
(AODV)
(SAODV)
Secure AODV (SAODV) Operation (1)
•
Timestamp
–
•
The timestamp is used to clear possible wraparound of the Message Sequence Number.
SAODV Digital Signatures
1.
Certification Setup
•
2.
Before entering the network, each node obtains a public key certificate from a
trusted certificate server (the trust third part, T)
C[S ]= [ IPS || PKS || T || te ]PVT
Route Discovery
•
•
•
End-to-end authentication between
source and destination
Hop-to-hop authentication between
intermediate nodes
Source only trusts destination to
choose return path
an example of secure ad hoc network
Secure AODV (SAODV) Operation (2)
•
SAODV Digital Signatures (Continue)
2. Route Discovery (continue)
•
•
Source broadcasts signed RDM (Route Discovery Message) along with its
own certificate.
RDM contains the source IP address, along with a source-specific nonce
(to detect duplicates)
S broadcasts RDM: = [RDM || IPD || C[S] || NS || t]PVS
•
First hop adds its own signature and certificate
A rebroadcasts RDM: = [[RDM || IPD || C[S] || NS || t]PVS]PVA || C[A]
•
Each hop verifies signature of previous hop and replaces it with its own –
also adds a reverse route to source
B rebroadcasts RDM: = [[RDM || IPD || C[S] || NS || t]PVS]PVB || C[B]
•
Destination also verifies the source signature
Secure AODV (SAODV) Operation (3)
•
SAODV Digital Signatures (Continue)
3. Route Reply (Route Setup)
•
Destination sends back a signed reply (RRM) to the first RDM received
D to C RRM: = [RRM || IPS || C[D] || NS || t] PVD
•
Again, RRM is signed by intermediate nodes, just like RDM – forward
path setup
C to B RRM: = [[RRM || IPS || C[D] || NS || t] PVD] PVC || C[C]
B to A RRM: = [[RRM || IPS || C[D] || NS || t] PVD] PVB || C[B]
•
Route discovered may not be the shortest, but is the “quickest” - likely to
be the least loaded / congested at the time
Secure AODV (SAODV) Operation (4)
•
SAODV Digital Signatures (Continue)
4. Route Maintenance
•
•
Nodes send signed error messages (RERR) to indicate link breaks, and
packets arriving on deactivated paths
ERR message contains IP address of originating node, along with its
signature – enables non-repudiation
A broadcasts B REER: =[RERR || IPS || IPD || C[A] || NA || t]PVA
•
•
Nonce included preventing replay attacks
Summary for AODV Vs SAODV
Summary for AODV Vs SAODV
• AODV Vs SAODV for Diagram
(AODV)
(SAODV)
Performance Analysis of Secure AODV (SAODV) (1)
•
–
–
–
–
–
–
–
•
–
–
–
–
–
Network Performance Parameters
•
•
Performance of SAODV compared with AODV
Simulations using OPNET Modeler 12.0 (Educational Version) simulator
MAC layer is the IEEE 802.11 MAC protocol with Distributed Coordination
Function (DCF)
Traffic sources are CBR (constant bit-rate)
Route packet processing delay: 2ms
Obtained through field testing of AODV
Digital signature generation delay: 8.5ms
Verification delay: 0.5ms
Measured running times of RSA digital signature and verification algorithms
Performance metrics
•
•
Packet Delivery Fraction
the Average Routing Traffic Received
the Average Route Discovery Time
Packet/Byte Overhead
Average Route Latency
Average Path Length
Average End-to-End Delay of Data Packets
Performance Analysis of Secure AODV (SAODV) (2)
Four Cases are simulated:
•
Case 1: Distribution of nodes within IEEE 802.11 b physical layer:
–
–
•
Scenario 1: Node Equalized Distribution
Scenario 2: Node Un-equalized Distribution
Case 2: Effect of node mobility within IEEE 802.11 b physical layer
–
–
•
Scenario 3: Uniform Mobility
Scenario 4: Random Mobility
Case 3: Effect of node moving speed within IEEE 802.11 b physical layer
–
Scenario 5: Based on Scenario 4 condition, with 3 different uniform node
velocities: 1m/s, 10m/s, and 20m/s to simulate
Case 1
Case 2
Case 3
Performance Analysis of Secure AODV (SAODV) (2)
The topology of Case 1
Simulation Results
the Average Routing Traffic Received (bits/sec)
Simulation Results
the Average Route Discovery Time
Simulation Results
the Average Packet/Byte Overhead
Simulation Results
the Average Route Latency
Simulation Results
the Average Path Length
Simulation Results
the Average End-to-End Delay of Data Packets
Case 4 Performance Analysis (1)
•
Case 4: Effect of different standard of physical layer :
–
•
Scenario 6: repeat the process of Scenario 1 ~ Scenario 5 with different
standard of physical layer and compare what the different results with
IEEE 802.11.b, IEEE 802.11.g and IEEE 802.11.a.
Key Results
An example of the Average Routing Traffic Received
(bits/sec) of Case 4 based on case 2 condition
• The efficiency of both AODV and SAODV with five metrics in IEEE 802.11a is
much lower than that in IEEE 802.11b and g .
• The efficiency in 802.11g is the same as that in 802.11b
Case 4 Performance Analysis (2)
•
Analysis
–
The relationship with the signal transmitted and received power, frequency,
and distance:
PR = PT / (2 * π * D * f / c)²
C is speed of light
D is the transmitted distance
F is transmission frequency
–
•
If power is the same, transmission frequency is higher, and then transmitted
distance should be lower. The frequency in 802.11a is 5GHz, and in 802.11b is
2.4 GHz. This means the transmitted distance in 802.11a is about a half of that
in 802.11b, in other word, that decreases the communication range. If using
the same topology as 802.11b, most nodes with 802.11a are out of transmission
range, and then the network connectivity decreases, thus, the average routing
received traffic, routing load and average throughput should be low.
Conclusion
IEEE802.11a is not profitable in ad hoc network/multi-hop networks to use
exclusively the high coding schemes (OFDM)
Case 4 Performance Analysis(3)
• Case 4 Effect of transmitted distance in ad hoc network
Case 4 Performance Analysis(4)
• Case 4 Effect of transmitted distance in ad hoc network (Continue)
• Conclusion
The transmitted distance
can affect route topology,
throughput, and
efficiency of the network
Effect of Malicious Node Behavior
•Performance metrics
_ simulations with 10 % malicious nodes for each protocol
_Average Path Length
_Routing Overhead
an example of SAODV with 20% malicious nodes (red and
yellow circled nodes)
Simulation Results
Average Path Length
• One of advantages of AODV is
to get the shortest path in ad
hoc network. But if this
network contained malicious
nodes, then non-shortest paths
would be selected.
• The average path length
increases 12.5% for AODV in
the 10% of malicious node, but
there is no change in SAODV
• This means malicious node
behavior can not affect SAODV
Simulation Results
Routing Overhead
• Longer routes can cause greater
routing overhead and longer
data packet delay.
• Routing overhead with 10% of
malicious nodes AODV is
larger than normal AODV, and
SAODV.
Conclusion and Future Works
Conclusion
•
•
•
Our SAODV is based on authentication, message integrity and
timeliness for an ad hoc environment as a part of a minimal security
policy to detect and protect against malicious actions by third parties
and peers in one particular ad hoc environment.
Our evaluations show SAODV has minimal performance costs for
the increased security in terms of processing and networking
overhead.
Our simulations based on five metrics proofed our SAOD is an
efficient protocol.
Future Works
•
Study what effects for AODV and SAODV with standards of
physical layer: IEEE 802.11family
•
Study the key management of ad hoc network
References
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
[1] C. E. Perkins and E. Royer, “Ad-hoc on-demand distance vector routing,” in Proc. of the 2nd IEEE Workshop on Mobile
Computing Systems and Applications, February 1999, pp. 90–100.
[2] E. Royer and C. Toh, “A review of current routing protocols for ad-hoc mobile wireless networks,” IEEE Personal
Communications, April 1999.
[3] D. Johnson and D. Maltz, “Dynamic source routing in ad hoc wireless networks,” Mobile Computing, vol. 353, pp. 153–
181, 1996.
[4] Z. J. Haas, “A new routing protocol for the reconfigurable wireless network,” in Proceeding of 1997 IEEE 6th
International Conference on Universal Personal Communications Record: Bridging the Way to
the 21st Century (ICUPC’97), October 1997, pp. 562–566.
[5] V. Park and M. Corson, “A highly adaptive distributed routing algorithm for mobile wireless networks,” in Proc. of
INFOCOM’97, 1997.
[6] C. E. Perkins and P. Bhagwat, “Highly dynamic destination-sequenced distance-vector routing (DSDV) for mobile
computers,” in Proceedings of the ACM SIGCOMM’94. ACM Press, 1994, pp. 234–244.
[7] R. Ogier, F. Templin, and M. Lewis, “Topology Dissemination Based on Reverse-path Forwarding (TBRPF),” Request for
Comments RFC 3684, February, 2004, February 2004.
[8] L. Zhou and Z. J. Haas, “Securing ad hoc networks,” IEEE Network Magazine, vol. 13, no. 6, November/December 1999.
[9] S. Wu, F. Wang, and B. Vetter, “Secure routing protocols: Theory and practice,” NC State Univ., Tech. Rep., April 1998.
[10] B. Schneier, Applied Cryptography: Protocols, Algorithms, and Source Code in C. 2nd Edition. John Wiley & Sons, Inc.,
1996.
[11] B. Schneier, Secrets and Lies: Digital Security in a Networked World.
1st Edition. John Wiley & Sons, Inc., 2000.
[12] R. Ramanujan, A. Ahamad, J. Bonney, R. Hagelstrom, and K. Thurber, “Techniques for intrusion-resistant ad hoc routing
algorithms (TIARA),” in IEEE Military Communications Conference, October 2000.
[13] S. Marti, T. Giuli, K. Lai, and M. Baker, “Mitigating routing misbehavior in mobile ad hoc networks,” in Proceedings of
MOBICOM 2000, August 2000.
[14] J.-P. Hubaux, L. Buttyan, and S. Capkun, “The quest for security in mobile ad hoc networks,” in MobiHoc ’01:
Proceedings of the 2nd ACM international symposium on Mobile ad hoc networking & computing, New York, NY, USA,
2001, pp. 146–155.
[15] J. Kong, P. Zerfos, H. Luo, S. Lu, and L. Zhang, “Providing robust and ubiquitous security support for mobile ad-hoc
networks,” in IEEE International Conference on Network Protocols (ICNP), November 2001.
[16] N. Asokan and P. Ginzboorg, “Key agreement in ad-hoc networks,” Computer Communications, vol. 23, no. 17,
November 2000.
[17] K. Fall and K. Varadhan, “ns notes and documentation,” available from http://www.isi.edu/nsnam/ns/, 2003.
[18] “IEEE Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications,” IEEE Std. 802.11-1997,
1997.
References
•[19] B. Tuch, “Development of waveLAN, an ISM band wireless LAN,” AT&T Technical Journal, vol. 72, no. 4, pp. 27–37, July-Aug. 1993.
•[20] J. Broch, D. A. Maltz, D. B. Johnson, Y.-C. Hu, and J. G. Jetcheva, “A performance comparison of multihop wireless ad hoc network routing protocols,” in Proc.
IEEE/ACM MOBICOM’98, October 1998, pp. 85–
•97.
•[21] Y. Hu, D. B. Johnson, and A. Perrig, “SEAD: Secure efficient distance vector routing for mobile wireless ad hoc networks,” in 4th IEEE Workshop on Mobile
Computing Systems and Applications, June 2002.
•[22] Y. Hu, A. Perrig, and D. B. Johnson, “Ariadne: A secure on-demand routing protocol for ad hoc networks,” in 8th ACM International Conference on Mobile
Computing and Networking (MobiCom 2002), September 2002.
•[23] F. Stajano and R. J. Anderson, “The resurrecting duckling: Security issues for ad hoc wireless networks,” in 7th Security Protocols Workshop, volume 1796 of Lecture
Notes in Computer Science, 1999, pp. 172–194,.
•[24] F. Stajano, “The resurrecting duckling - what next?” in Security Protocols - 8th International Workshop, April 2001.
•[25] D. Balfanz, D. Smetters, P. Stewart, and H. C. Wong, “Talking to strangers: Authentication in ad-hoc wireless networks,” in Network and Distributed System Security
Symposium Conference Proceedings,
•February 2002.
•[26] M. Steiner, G. Tsudik, and M. Waidner, “Key agreement in dynamic peer groups,” IEEE Trans. Parallel Distrib. Syst., vol. 11, no. 8, pp. 769–780, 2000.
•[27] S. Yi, P. Naldurg, and R. Kravets, “Security-aware ad hoc routing for wireless networks, Tech. Rep. UIUCDCS-R-2001-2241, August 2001.
•[28] P. Papadimitratos and Z. Haas, “Secure routing for mobile ad hoc networks,” in SCS Communication Networks and Distributed Systems Modeling and Simulation
Conference (CNDS 2002), January 2002.
•[29] L. Venkatraman and D. P. Agrawal, “Security scheme for routing in adhoc networks,” in Proceedings of the 13th International Conference on Wireless
Communications, July 2001, pp. 129–146.
•[30] B. Dahill, B. Levine, C. Shields, and E. Royer, “Secure routing protocol for ad hoc networks,” U Mass, Tech. Rep. UM-CS-2001-037, 2001.
•[31] B. Smith and J. Garcia-Luna-Aceves, “Securing the border gateway routing protocol,” in Proceedings of Global Internet, November 1996.
•[32] B. Smith, S. Murthy, and J. Garcia-Luna-Aceves, “Securing distancevector routing protocols,” in Proceedings of the Symposium on Network and Distributed System
Security (SNDSS’97), February 1997, pp. 85–92.
•[33] S. Murphy and M. Badger, “Digital signature protection of the OSPF routing protocol,” in Proceedings of the Symposium on Network and Distributed System Security
(SNDSS’96), February 1996, pp. 93–102.
•[34] R. C. Merkle, “A digital signature based on a conventional encryption function,” in Advances in Cryptology-CRYPTO’87, August 1987.
•[35] S. Cheung, “An efficient message authentication scheme for link state routing,” in 13th Annual Computer Security Applications Conference, 1997.
•[36] R. Hauser, T. Przygienda, and G. Tsudik, “Reducing the cost of security in link-state routing,” in Symposium on Network and Distributed System Security (SNDSS’97),
February 1997, pp. 93–99.
•[37] L. Reyzin and N. Reyzin, “Better than BiBa: Short one-time signatures with fast signing and verifying,” in Information Security and Privacy-7th Australasian
Conference ACSIP, 2002.
•[38] K. Zhang, “Efficient protocols for signing routing messages,” in Proceedings of the 1998 Internet Society (ISOC) Symposium on Network and Distributed System
Security, March 1998.