Study and Implementation of Efficient Security for Wireless Networks

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Study and Implementation ofEfficient Security
for Wireless Networks
M. Razvi Doomun Faculty of Engineering University
of Mauritius r.doomun_at_uom.ac.mu Project
Supervisor Prof. K.M.S. Soyjaudah
Research Week 2009/2010 Doctoral Consortium
e-Poster
12/28/2013
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Objectives

• Design efficient security and privacy mechanisms
  for resource-constrained wireless networks
• Analysis of operational complexity and efficiency
  of IEEE 802.11i security protocol
• Propose integrated security and privacy of source
  and destination in ad hoc wireless networks
  against global attackers.

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Energy-efficient security protocol can be
achieved by

• Software optimization techniques and better
  hardware implementation, or a combination of
  both, for constituent cryptographic operations.
• Use equivalent alternative cipher primitives that
  consume less energy
• Reduce workload of a security protocol
• Modify or simplify the structure of security
  protocol components
• Frame formatting, minimize redundant operations
  and overheads
• Innovative and energy-aware security provisioning
  with flexible security framework
• Different combinations of security primitives for
  different security requirements at different
  operating conditions

M. R. Doomun, K.M.S. Soyjaudah, Adaptive IEEE
802.11i security for energy-security
optimization, In Proceedings of The Third
Advanced International Conference on
Telecommunications AICT 07, IARIA- Mauritius,
13-19 May, 2007.
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General Energy Cost of Security Protocol
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Comparative complexity of WEP, TKIP, AES-CCMP

• Complexity of TKIP is proportional to the message
  size encrypted
• With message size less than 100 bytes, TKIP has
  faster execution speed than AES-CCMP
• Complexity of CCMP increases linearly with
  increasing key length, more encryption rounds, as
  well as larger payload size.
• CTR-mode and CBC-MAC contributes almost equally
  to the overall complexity of CCMP

M. R. Doomun, K.M.S. Soyjaudah, D. Bundhoo,
Energy Consumption and Computational Analysis of
Rijndael-AES, In Proceedings of Third IEEE
International Conference in Central Asia on
Internet The Next Generation of Mobile, Wireless
and Optical Communications Networks, September
26-28, 2007. M. R. Doomun and K.M.S. Soyjaudah,
Analytical Comparison of Cryptographic
Techniques for Resource Constrained Wireless
Security, International Journal of Network
Security, Vol.9, No.1, pp. 8294, July 2009.
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Complexity comparison of WEP, TKIP and CCMP
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M. R. Doomun, K.M. Sunjiv Soyjaudah, Modified
Temporal Key Integrity protocol for efficient
wireless network security, In Proceedings of
International Conference on Security and
Cryptography (SECRYPT 2007) IEEE, Spain, 28-31
July 2007. M. R.Doomun and K.M.S. Soyjaudah
LOTKIP Low Overhead TKIP optimization for
Wireless Ad hoc Networks International Journal
of Network Security (IJNS).
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Communication Privacy

• Traffic analysis in large wireless ad hoc
  networks
• Passive attack
• Reveal contextual information
• Direction of traffic flow, nodes with high packet
  transmission rate
• Locate of source and destination nodes
• Traffic analysis countermeasures
• Use multipath to spread the network traffic
• Use anonymous routing techniques
• All packets encrypted link-by-link

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Two types of attackers

• Local attacker
• Eavesdrop on transmitted packets around one node
  at a time
• Does not know the overall network traffic flow
• Global attacker
• Visualize the overall network traffic flow
• Capable of network-wide traffic rate monitoring
  and time-correlation attacks.
• Network-wide rate monitoring attack involves
  counting the number of transmitted/received
  packets around every node in the network.
• Time-correlation attack involves finding the
  communication patterns by analyzing latencies
  between packet transmissions around nodes in the
  network.

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Models and Assumptions (1)

• Network model
• Ad hoc grid-distribution or random-distribution
  network nodes
• MAC and routing protocol messages are encrypted
• Assume existing key management protocol that can
  distribute pair-wise keys between nodes or
  public-private key pairs for each node
• All packets are transmitted in the same format
  and have same length (by padding or fragmenting).
  
• Route discovery communications are assumed to be
  anonymous using any of the anonymous routing
  protocols

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Models and Assumptions (2)

• Attacker Model
• An external, global, and powerful attacker model
• Attacker is passive and cannot compromise nodes
  in the network
• Knowledge of network topology and can keep
  statistical measurements for all of the network
  traffic
• A possible method for this attack is by deploying
  an overlay network with several malicious nodes
  simply to sense traffic from the given ad hoc
  network

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Privacy Evaluation Metrics

• Anonymity
• The level of anonymity is defined as the
  probability that a node of interest is
  incorrectly identified in an anonymous group
• Depends on the number of nodes in the anonymous
  zone
• If a node is hidden among A nodes that have the
  same behavior, then the level of anonymity
• Unlinkability
• 3-D graph of transmitted data around nodes to
  determine whether or not a global attacker can
  visualize the existence of communication between
  a source and destination.
• Edge detection algorithms to extract traffic
  pattern
• Entropy
• If node i transmits ui packets and a total of V
  packets were transmitted in the network in time
  T, the fraction of packets sent by i is pi ui/V
  and the entropy is defined as

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Privacy Protocol (1)

• Initialization
• Source node S broadcasts a hello message to
  discover all its one-hop neighbors N(1, i) for i
  1,2, , m, where m is the total number of
  neighbor nodes.
• The nodes in N(1, i) discover their respective
  neighbors N(2, i) which are two-hops away from
  node S.
• Consequently, source node S constructs the list
  N(1, i),N(2, i),N(3, i), , N (k, i), where N(k,
  i) is the set of kth hop neighbors of node S.
• This initialization process of neighbor discovery
  is done periodically by all nodes in the network.
  

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Privacy Protocol (2)

• Cloud Construction
• Let the cloud region be of maximum width k hops
  from the source S.
• For e.g, with k 3, source node S will randomly
  select a number of nodes, B lt 4k(k1), such that
  B ? N(1, i) ? N(2, i) ? N(3, i).
• Nodes in cloud B
• Marked as pseudosources in the cloud
• Requested to transmit encrypted dummy packets at
  a rate similar to the source transmission rate
• Forward real packets when available from source
  to delegated sources.
• Drop dummy packets.

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Privacy Protocol (3)

• Destination node D do same initialization
  procedure also construct a cloud.
• Size of the source and the destination clouds can
  be different.
• Delegated Source and Delegated Destination
• Node S randomly selects one or more nodes from
  the set B to act as delegated sources.
• (D will do the same)

R. Doomun, T. Hayajneh, P. Krishnamurthy and D.
Tipper, SECLOUD Source and Destination
Seclusion using Clouds for Wireless Ad Hoc
Networks, IEEE Symposium on Computers and
Communications (ISCC) Tunisia, 5-8 July, 2009.
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Simulation

• 400 nodes distributed in an area of 2000m x 2000m
  with average node degree between 7 and 8.
• Quasi-Unit disk graph (Q-UDG)
• The source sends 5000 data packets in a time
  window of T seconds
• The attacker
• Will sample n of the nodes that have the highest
  number of packets transmitted in T and computes
  the average value U of packets transmitted.
• Will mark nodes that transmit at least ßU
  packets where 0ltßlt 1.
• Will vizualize graph of nodes, the number of
  packets transmitted and the marked nodes to
  determine possible communication paths, sources,
  and destinations.
• We pick n 10 in our simulations. Different
  values of n and ß will create sharp or fuzzy
  boundaries in the graph

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Results Privacy Technique
With single Source-Destination
With multiple paths
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Example of Security-Privacy Policy Decision Matrix
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Conclusions

• Complexity overhead analysis of existing 802.11i
  wireless security mechanisms
• Optimizing execution of TKIP and AES-CCM
  algorithm by minimizing redundant operations and
  reducing communication overhead
• E.g. Low Overhead TKIP Resource Saving AES-CCMP
  Design with Hybrid Counter Mode Block Chaining
  MAC
• Anonymity level and transmission overhead
  analysis of existing communication privacy
  mechanisms
• Communication overhead cannot be reduced without
  sacrificing some privacy strength because hiding
  traffic pattern comes at a cost.
• Future / Ongoing work
• Develop privacy techniques for better seclusion
  for both, source and destination nodes location
• Adaptive and resource-aware security-privacy
  model provides more efficient energy consumption