C.O.B.R.A.

• Kyle Morse

• Matthew Denker

• Mark Srebro

• Derrick Chiu

Dynamic Source Routing

Problem

• Develop a simple and efficient multi-hop wireless ad hoc networking protocol

• Account for range, mobility, and the lack of a server

• Minimize overhead

• Localize error correction

Solution 1• Develop a pair of algorithms that work together to form the basis of DSR

– Route discovery• Each node holds a list of known routes to various destinations. If the definition is not in the route, begin

a recursive search for a new route.

– Route maintenance• When a route no longer becomes viable, request new routes and update known route tables.

A B C D E“A” “A,B” “A,B,C” “A,B,C,D”

“ID=2” “ID=2” “ID=2” “ID=2”

Route Discovery example: Node A is the initiator, and node E is the target.Taken from “DSR: The Dynamic Source Routing Protocol for Multi-Hop Wireless Ad Hoc Networks

A B C D

Route Maintenance example: Node C is unable to forward a packet from A to E over its link to next hop D.

Taken from “DSR: The Dynamic Source Routing Protocol for Multi-Hop Wireless Ad Hoc Networks

E

Solution 2

• Overhead minimization– Listen for new transactions before replying with a route (random timings)– Introduce a “hop limit” for routing route requests– Allow automatic route shortening – if a node overhears a packet going

around it. It can drop itself from future routes when nodes request a route.• Data integrity

– Allow for package salvaging by letting nodes with a route error search for a new route in their cache and forward the packet again. This has a single salvage limit so loops are not formed.

• Miscellany– Algorithm allows for multiple interfaces, as long range hops appear the

same as short range hops to the protocol.– Connections exist for nodes to be edge nodes, thus giving access to the

internet at large.

On Demand Multipath Routing for Mobile Ad Hoc Networks

The Problem:

-Routes unreliable in Ad Hoc networks

-Network floods for routes

-Performance hit

Bandwidth is precious in Ad Hoc

On Demand Multipath Routing for Mobile Ad Hoc Networks

Solution:

- Modify DSR(Dynamic Source Routing)

- Nodes initially do flood requests as before

but more than a single path is returned

- Nodes decide a primary shortest path and

store a given number of alternates

- Intelligent clean-up on route failure

On Demand Multipath Routing for Mobile Ad Hoc Networks

Results:

- Increase in time between route discoveries across

the board. Although decreases with path length.

- Keeping 2 alternates found to be optimum setting.

Energy Conserving Routing in Wireless Ad-Hoc Networks

Energy Conserving Routing in Wireless Ad-Hoc Networks

The Problem:

- Ad-Hoc revolves around mobility this introduces

a new limited resource battery life.

- Current ECR focuses on the battery life of

a single node.

Energy Conserving Routing in Wireless Ad-Hoc Networks

Solution:

- Focus on the life of the ad-hoc network as a system

- Flow Augmentation and Redirection

- Creates a tradeoff between searching for the best EC

route and the route that spares nodes with not little

energy left.

Energy Conserving Routing in Wireless Ad-Hoc Networks

Results:

- Life of important nodes were lengthened allowing

the system life to be increased on an average of 60%

- Focused on overall network connectivity

Secure Routing for MANETs

• Panagiotis Papadimitratos, Zygmunt J. Haas

• No server:– Authenticate? Route?

• Malicious Activity:– False topology broadcasts– Nodes drop/misroute packets– Nodes corrupt packets

Secure Routing Protocol (SRP)

• Shared, symmetric key – Elliptic Curve Diffie-Hellman algorithm

• Route request packet:– Query sequence #, random query ID– These + key MD5/SHA-1 send packet!

• Intermediate nodes pass along• Destination verifies MAC, sends reply over

reverse path

Why it’s good

• Node priority system – eliminate malicious activity

• Computation isolated to end nodes

• Guaranteed correct network topology

• Quick route breakage discovery

Secure Efficient Ad hoc Distance vector routing protocol (SEAD)

• Stands for Secure Efficient Ad hoc Distance vector routing protocol.

• Based on Destination-Sequenced Distance-Vector routing protocol with Sequence numbers (DSDV-SQ)

• Prevents nodes from sending out malicious routing tables.

• Prevents Denial-of-Service (DoS) attacks through the low use of computing resources.

SEAD

• Uses hash chains to authenticate routing table entries.

• First hash value in hash chain is computed using a randomly generated value.

• Sequence number determines the block in the hash chain to use.

• Metric determines the hash in that block to use.

SEAD

• Node sends the first element of its hash chain in its own entry in the routing table.

• For all other entries, nodes compute and send the hashes of received hash values based on sequence number and metric.

• Receiver authenticates hash value in new entry using hash value in old entry by recreating the new hash value using the old.

C.O.B.R.A Team Project

• Create a twenty first century version of a classic Bonzai! Type game.– Players are positioned as islands with a fortress

and cannon.– Fire cannons at other fortresses and try to get

hits.

• Use SEAD to securely manage the routing of shots (messages) between clients.

Chosen Papers• “SEAD: Secure Efficient Distance Vector Routing

for Mobile Wireless Ad Hoc Networks”– Yih-Chun Hu David B. Johnson Adrian Perrig

• “On Security Study of Two Distance Vector Routing Protocols for Mobile Ad Hoc Networks”– Weichao Wang, Yi Lu, Bharat K. Bhargava

• “Highly Dynamic Destination Sequenced Distance Vector Routing

DSDV for Mobile Computers”– Charles E Perkins, Pravin Bhagwat

• “Efficient Constructions for One-way Hash Chains”– Yih-Chun Hu Markus Jakobsson Adrian Perrig

Our Website

• http:www.cs.rit.edu/~krm4686/adhoc/