1. Mesh Security Recommendation
Month Year
doc.: IEEE yy/xxxxr0
May 2006
Mesh Security Recommendation
Date:
Authors:
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Walker and Zhao, Intel Corporation
John Doe, Some Company

2. Month Year
doc.: IEEE yy/xxxxr0
May 2006
Abstract
This submission summarizes provides a security recommendation to IEEE TGs.
Walker and Zhao, Intel Corporation
John Doe, Some Company

3. Month Year
doc.: IEEE yy/xxxxr0
May 2006
Where we are
Transport and AP security appear to be well-understood problems
We believe i can be readily adapted to secure transport and mesh formation
We believe adding AP security into s is straight-forward
Walker and Zhao, Intel Corporation
John Doe, Some Company

4. Month Year
doc.: IEEE yy/xxxxr0
May 2006
Where we are
Security for forwarding and routing analysis has started but is not complete
See doc by Meiyuan Zhao
Technology solutions to all security issues raised by fowarding and routing do not appear to exist
Every few days we discover new unsolved security problems in the forwarding and routing space
These are insider attacks caused by compromise of mesh nodes
Realistic because of the lack of physical security for mesh nodes
External routing appears to be a research problem
It may be years before we understand how to approach this problem
We don’t know how long the process of understanding the space will take
Walker and Zhao, Intel Corporation
John Doe, Some Company

5. Motivating Example: Misrouting leads to looping
Month Year
doc.: IEEE yy/xxxxr0
May 2006
Motivating Example: Misrouting leads to looping
Attack Overview
Combine efforts by routing and forwarding
Change the message propagation direction
Message authentication can’t help!
Step 1: S sends RREQ broadcast to
establish a route to D
Step 2: RREQ is passed on by B,
A, and C
Step 3: F propagates RREQ from B
Step 4: A keeps this RREQ, knowing
that two paths to S exist
Step 5: D sends back RREP to C,
then A
Step 6: A forwards RREP to F
Step 7: A route {S, B, F, A, C, D} is
established
Step 8: S sends data to D
Step 9: A forwards the data to B
S, 1, S
S, 2, B
S, 3, F
D, 4, F
D, 2, C S B A C D F
S, 2, B
D, 3, A
Walker and Zhao, Intel Corporation
John Doe, Some Company

6. Recommendation Recommend TGs to
Month Year
doc.: IEEE yy/xxxxr0
May 2006
Recommendation
Recommend TGs to
Develop mesh transport security, by adapting i to its needs
Including the mesh formation aspects governed by secure link establishment
Extend AP security, by defining new AP state machines, so that the AP service is only available when the AS is reachable from the AP
To address issues that are only implicit in the wired infrastructure case
Satisfy the PAR
When the understanding of mesh routing/forwarding matures, export security for Routing and Forwarding outside of TGs
Walker and Zhao, Intel Corporation
John Doe, Some Company

7. Straw Poll TGs to follow this recommendation For: Against: May 2006
Month Year
doc.: IEEE yy/xxxxr0
May 2006
Straw Poll
TGs to follow this recommendation
For:
Against:
Walker and Zhao, Intel Corporation
John Doe, Some Company

8. Backup May 2006 Month Year doc.: IEEE 802.11-yy/xxxxr0
Walker and Zhao, Intel Corporation
John Doe, Some Company

9. Forwarding Threats May 2006 Month Year doc.: IEEE 802.11-yy/xxxxr0
Dropping
Selectively
Dropping
Misroute
Header
forgery/
modification
Starvation
Partition/cut
Delay
forwarding
blackhole
Instability
Looping
Practical
limited
Very limited
Walker and Zhao, Intel Corporation
John Doe, Some Company

10. Motivating Example: Misrouting leads to looping
Month Year
doc.: IEEE yy/xxxxr0
May 2006
Motivating Example: Misrouting leads to looping
Attack Overview
Combine efforts by routing and forwarding
Change the message propagation direction
Message authentication can’t help!
Step 1: S sends RREQ broadcast to
establish a route to D
Step 2: RREQ is passed on by B,
A, and C
Step 3: F propagates RREQ from B
Step 4: A keeps this RREQ, knowing
that two paths to S exist
Step 5: D sends back RREP to C,
then A
Step 6: A forwards RREP to F
Step 7: A route {S, B, F, A, C, D} is
established
Step 8: S sends data to D
Step 9: A forwards the data to B
S, 1, S
S, 2, B
S, 3, F
D, 4, F
D, 2, C S B A C D F
S, 2, B
D, 3, A
Walker and Zhao, Intel Corporation
John Doe, Some Company

11. Month Year
doc.: IEEE yy/xxxxr0
May 2006
Defense
Ordinary message authentication scheme can’t help against this attack
Root problem: no mechanism to protect information about topology
These are perfectly authentic messages, I’m just not going to send them in the right direction
Problem for link-state, distance vector routing protocols
We need to utilize additional information
Carry source route in data frame: “hey, you are not suppose to forward this data to me”
Use unique sequence numbers to detect loops: “hey, I’ve forwarded this data before”
Walker and Zhao, Intel Corporation
John Doe, Some Company

12. So…possible approach (1)
Month Year
doc.: IEEE yy/xxxxr0
May 2006
So…possible approach (1)
Source route
Change routing protocol to provide source route
A authentication scheme to this information from forgery
A key provisioning scheme to support source route authentication
Does not introduce additional vulnerabilities subject to DoS attack
With source routing protocol, can we prevent the loop from being established? YES
Walker and Zhao, Intel Corporation
John Doe, Some Company

13. Possible approach (2) Sequence number approach
Month Year
doc.: IEEE yy/xxxxr0
May 2006
Possible approach (2)
Sequence number approach
Add unique sequence number to each data frame (done)
Intermediate nodes and destination node should verify its uniqueness
A authentication scheme on data frame header
Minimize storage requirements on forwarding nodes
This approach mitigate the threat consequences in terms of resource consumption
But this can’t prevent looping
The network is still not available for victim nodes
Walker and Zhao, Intel Corporation
John Doe, Some Company

14. Thoughts on Mesh Architecture
Month Year
doc.: IEEE yy/xxxxr0
May 2006
Thoughts on Mesh Architecture
Packing many functions into one layer causes security problems
Size of the network matters
Dense, small networks seem to have fewer severe routing problems
Attacks are likely to succeed in sparse, large networks
Walker and Zhao, Intel Corporation
John Doe, Some Company