SecurityAware AdHoc Routing for Wireless Networks

1
Security-Aware Ad-Hoc Routing for Wireless
Networks

• Seung Yi et al
• Department of Computer Science, UIUC
• Nov 25, 2002
• Uichin Lee
• CA-LAB CS KAIST

2
Agenda

• Introduction
• Motivation
• Security-Aware Ad-hoc Routing (SAR)
• Implementation
• Performance Evaluation

3
Introduction

• Ad-hoc Network Characteristics
• 1. No infrastructure support
• 2. Limited resources (power, memory, and
  processing)
• 3. Easily eavesdropped
• 4. Naïve trust model
• Examples
• Hostile environments like battlefields or rescue
  operations

4
Motivation

• Ad-hoc network routing protocols based on
  characteristic 1 and 2 demand new metrics for 3
  and 4
• Legacy models mostly has used distance measured
  in hops without considering security
• Along with above we can explore the use of
  different security attributes to improve the
  quality of security
• An approach to routing that incorporates security
  levels of nodes into legacy routing metrics

5
Motivation

• Quality of security based on protection level

6
Security Aware Ad-hoc Routing Protocol

• Basic idea
• Applications are able to specify the protection
  level of their ad-hoc route with respect to
  metrics that are relevant to them
• Ad-hoc On-demand Distant Vector Routing (AODV)
• RREQ (Route Request) ? RREP (Route Reply)
• Caching the route on intermediate routers
• Embed security metrics into the RREQ and RREP
  packet and change the forwarding behavior

7
Security Aware Ad-hoc Routing Protocol Metric

• Trust level
• Mirror the organizational hierarchy mapped into
  privilege levels or use QoP bit vector
• Assumption
• Trust level in RREQ and RREP is immutable
• Some mechanism to distribute keys and share
  secrets is already in place
• Metrics
• Timeliness timestamp
• Ordering sequence number
• Authenticity password, certificate (forming
  trust relationship)
• Integrity digest, digital signature
• Confidentiality encryption

8
Implementation (1/3)

• An addition field, RQ_SEC_REQUIREMENT indicating
  the required security level for the route in RREQ
• If the intermediate node cannot satisfy the
  security requirement, the RREQ packet is dropped
• Forwarding nodes update RQ_SEC_GUARANTEE of the
  RREQ packet showing the maximum level of security
  by the discovered path

9
Implementation (2/3)

• The arrival of a RREQ packet at the destination
  means the existence of path
• The value of the RQ_SEQ_GUARANTEE field in RREQ
  is copied to RP_SEQ_GUARANTEE filed in RREP
• When the RREP packet arrives at an intermediate
  node in the reverse path, it updates their
  routing table with new RP_SEQ_GUARANTEE

10
Implementation (3/3)

• Example
• Not optimal and reduced number of paths

RREQ 10 / 7
RREQ 10 / 12
7
12
RREQ 10 / 7
10
RREQ 7 / -
RREP 7
10
Destination
Source
6
level
Drop
11
Performance Evaluation

• Simulation setup
• 50 nodes moving around in 670m by 670m region
  with random walk model
• Consisting of three levels viz., high, medium,
  and low each with 15, 15, and 20 nodes
  respectively
• Modifying the original AODV in ns2
• Send the same amount of data about 10,000 packets
  at the same rate consisting of 20 flows
• Traffic pattern 1 high 10 medium 20 low 70
• Traffic pattern 2 high 33 medium 33 low 34

12
Performance Evaluation SAODV Processing
Overhead

• Overall simulation time
• Path discovery
• Routing message overhead

13
Performance Evaluation Secure Routing
Measurements

• Message integrity signed hash digest
• Confidentiality encrypting packets
• Nodes that have the same trust level share the
  same encryption level
• Overall simulation time and transmitted data

14
Conclusion

• SAR enables the discovery of secure routes in a
  mobile ad-hoc environment
• Security metrics allow applications to enforce
  explicit cooperative trust relationships
• Can easily be fit into existing routing protocols
  such as DSR and AODV
• The processing overheads in SAR are offset by
  restricting the scope of the flooding