SPLASH Project INRIA-Eurecom-UC Irvine November 2006.

SPLASH ProjectINRIA-Eurecom-UC Irvine

November 2006

SPLASH project review

• Security of Wireless Adhoc Networks– From MANET security…– To WSN (Wireless Sensor Network) Security!

• Many contributions in many different areas...

Outline

• MANET Security– Membership Management– Collaboration Enforcement

• WSN Security– The security Challenges– Secure Aggregation

• Conclusions

What is a MANET?

• No centralized control• No hierarchy• Fault-tolerant• Dynamic membership

MANET

Distributed and scalable security services required

•Set of nodes (5-50) that establishA network•Wireless and multi-hop•Does not rely on any fixed infrastructure•Spontenuous (no prior association)

MANET two main Security Challenges

• Membership Management– How does a new node become a member of

the MANET without relying on a trusted membership controller?

• Secure Routing/Collaboration Enforcement– How can we make sure that all node

collaborate i.e. relays others’ packets?

Membership Management: The Centralized Approach

AB

C

D

E

F

Membershipmanager

Our Approach:Distributed Membership Management

AB

C

E

F

Our approach:Admission Control

• Step 1: Join request

• Step 2: Join commit (Vote)

• Step 3: GMC issuance & share acquisition

MnewMnew

• New member (Mnew) wants to join the group• A quorum of t current members need to issue Mnew

a group membership certificate (GMC)• If no quorum found, membership is denied

Vote1Vote2

Vote2Vote2

Contributions• Solution based on secret sharing technique +

polynomial interpolation.– Only One round (instead of t) is necessary to

become a member of the group.• Once a node becomes a member it receives a

token (private key) that can be used to:– Vote for new member – Establish a key with any other MANET member– Prove membership

• More infos?:– Robust Self-Keying Mobile Ad Hoc Networks,

Claude Castellucia, Nitesh Saxena, and Jeong H. Yi, Elsevier Computer Networks, April 2007.

Secure Collaboration

• How to make sure that members are not selfish?– Some nodes might drop packets to save

energy or to perform DoS attacks

• We have developped:– a reputation based solution (CORE)– a Cryptographic solution

How to enforce collaborations?

• Problem statement:

A

B

CC A

How to enforce collaborations?

• Problem statement:

A

B

C

C A

Our solution• Some packets addressed to B are routed via C

– Boomerang routing ;-)

AC

B

C A B A

A

C

B

C A B A

B A

Our solution• If B drops packets…it may drop some of its packets …• It is forced to collaborate since he does not know the final

destination…

• Reference: Pocket bluff (INRIA Research Report)

A

C

B

C A B A

Wireless Sensor Networks

• Another type of adhoc networks• Network of sensors that usually monitor the environment• Sensors are very small and cheap devices• They usually send their monitored data to the sink (a

more powerful device)

Application Spectrum

HazardDetection

BiologicalMonitoring

Linear StructureProtection

SmartEnvironment

WearableComputing

ImmerseEnvironments

Earth Science &Exploration

Context-AwareComputing

Interactive VRGame

Wireless SensorNetworks

Urban WarfareMilitary Surveillance

Disaster RecoveryEnvironmental Monitoring

MANET vs WSN• MANET and WSN look similar but they are quite

different..

MANET WSN

Nodes are MobileNodes are Fixed

10-50 Nodes

1000/10000 Nodes

Nodes belong to same entity

Nodes belong to different entities Nodes sends to BS

P2P communication

Nodes can easily be physically corrupted

Nodes have very Limited CPU/memory/energy

Manet Security Challenges

• MANET WSN

Access/Membership control Scalability

Collaboration enforcement/Secure routing

Energy/CPU efficient security protocols

Sensor revocation

Some Contributions

• Key establishment/pairing– Shake them Up! (presented last year)

• Secure Aggregation– Aggregation is a useful technique to save energy– User is often more interested in the aggregate (i.e.

average in a give area) than each individual value– Instead of sending each value to the sink, the values

are added by intermediate nodes…– Less packets are transmitted, i.e. energy is saved…

Secure Aggregation• Aggregation is simple without security

– Intermediate nodes process data of their children• But what happens if the data sent by each sensor is encrypted using

a key that it shares with the sink?– Data processing is no more possible…or is it?– We’ve developed a new additively homomorphic cipher

• Enc(k1, msg1) + Enc(k2, msg2) = Enc(k1+k2, msg1+msg2)• Intermediate nodes can add the ciphers they receive from children …and the

sink can still recover the sum of the plaintexts.• But intermediate nodes do not have access to the plaintext values, i.e.

privacy is provided…

• More info?: – Efficient Aggregation of Encrypted Data in Wireless Sensor

Networks, Conference Presentation Mobiquiotous 2005, July 2005

Conclusions• The SPLASH project was a very productive and

successful project– Pars Mutaf (INRIA) visited Eurecom for 1 year.– Claude Castelluccia (INRIA) visited UCI for 2 years.

• The scientific contributions were numerous and many papers were published

• We participated in many conf. PC and launched ESAS (Europeen Workshop on Security in Adhoc and Sensor Network)

• We have deployed 2 testbeds– MANET (Eurecom) to evaluate CORE– WSN (INRIA)

Some Papers• Key distribution/Membership Management in MANET

– Robust Self-Keying Mobile Ad Hoc Networks, Elsevier Computer Networks, April 2007.

– Ad hoc network security, book chapter in Mobile Adhoc networking, 2004 and in Handbook of Information Security (2006).

• Secure and Private MANET routing protocol– Packet coding for strong anonymity in ad hoc networks, IEEE Securecomm

2006, – Securing Route Discovery in DSR, IEEE Mobiquitous'05

• Collaboration Enforcement in MANET– CORE: a collaborative reputation mechanism to enforce node cooperation in

MANET (Michiardi phd thesis, 2004 + 6-7 publications)– Pocket Bluff, INRIA Tech. Report, 2005.

• WSN Security– Shake Them Up! Mobisys 2005.– Efficient Aggregation of Encrypted Data in Wireless Sensor Networks

IEEE Mobiquitous'05 – Authenticated Interleaved Encryption, eprint, 2006.– More to come soon ;-)

Visibility

• European Workshop on Security in Ad-Hoc and Sensor Networks (2004)– Refik Molva and Gene Tsudik (UCI) were chairing

ESAS2005– C.Castelluccia is in the steering com.– ESAS and IEEE WISE will merge to create an new

IEEE conference: IEEE WISEC (Wireless Security)!

• We have chaired/were in the PC on numerous conf./workshop: Securecom, Mobiquitous, ESAS, Globecom, UbiSec,…