Secure Autoconfiguration and Routing in an

IPv6-Based Ad Hoc Network

Jehn-Ruey Jiang

National Central University

Outline IPv6 Overview Ad Hoc Networks IP Autoconfiguration CGA S-DSR Conclusion

Outline IPv6 Overview Ad Hoc Networks IP Autoconfiguration CGA S-DSR Conclusion

Internet History 1969: ARPANET (using Network Control Protocol, NCP) 1974: TCP/IP (by Vinton Cerf and Bob Kahn) 1981: IPv4 (RFC 791) 1984: NSFNet (using Transmission Control

Protocol/Internet Protocol, TCP/IP) 1990: ARPANET retired 1991: WWW (World Wide Web) (by Tim Berners-Lee) 1993: NCSA Mosaic (by Mark Andreesen) → Netscape

Navigator 1990s: Internet 2000s: internet

IPv6 History 1992: IPng (Next Generation IP) began in IETF (Internet

Engineering Task Force) working groups 1994: IPv6, announced by IESG(Internet Engineering

Steering Group) (RFC 1752) (IPv5 is for a stream protocol)

1998: IP Version 6 Addressing Architecture [July] (RFC2373)

1998: Internet Protocol, Version 6 (IPv6) Specification [December] (RFC2460)

IPv6 Features Expanded address space

128 bits ( 3.4*1038 IP Addresses) Auto-configuration

Stateless (Prefix + EUI-64), Stateful (DHCPv6), Addressing Lifetime (Age for renumbering)

Quality of Service 20-bit Flow Label enables identification of traffic flows for real-time Voice and Video stream

Integrated Security SupportIPSec(AH Header+ESP Header)

MobilityNo Foreign Agent, Free of Triangle routing, Plug&Play (Care-of Address)

IPv6 Vision

Source: NDHU

IPv6 IPv6 Anything, Anytime, Anywhere Anything, Anytime, AnywhereConnection to Internet Connection to Internet

Outline IPv6 Overview Ad Hoc Networks IP Autoconfiguration CGA S-DSR Conclusion

Ad hoc Networks

Ad hoc: formed, arranged, or done (often temporarily) for a particular purpose only

Ad Hoc Network (MANET):A collection of wireless mobile hosts forming a temporary network without the aid of established infrastructure or centralized administration

Infrastructure vs Ad-hoc Modesinfrastructure network

ad-hoc network

APAP

AP

wired network

ad-hoc network

Multi-hop ad hoc network

Applications of MANETs

Battlefields

Disaster rescue

Spontaneous meetings

Outdoor activities

MANET Routing Protocols

Table Driven (Proactive)

DSDV, FSR

On Demand (Reactive)

AODV, TORA, ABR, SSA

Hybrid

ZRP

Secure Routing Protocols

SAODVSRPSARCSERSEADAriadeneBSAR

Outline IPv6 Overview Ad Hoc Networks IP Autoconfiguration CGA S-DSR Conclusion

Stateful vs. Stateless

Stateful

DHCPv6

Stateless

DAD (Duplicate Address Detection)

DAD (1/3)

A function of NDP (Neighbor Discovery

Protocol)

Two types of messages

NS (Neighbor Solicitation)

NA (Neighbor Advertisement)

DAD (2/3)

Neighbor Solicitation

Host B

Host ATentative IP: FE80::2AA:FF:FE22:2222

IP : FE80::2AA:FF:FE22:2222

(multicast)

Ethernet Header: Dest. MAC is 33-33-FF-22-22-22IPv6Header: Source Address is :: Destination address is FF02::1NS Header : Target Address is FE80::2AA:FF:FE22:2222

DAD (3/3)

Neighbor Advertisement

Host B

Host ATentative IP: FE80::2AA:FF:FE22:2222

IP : FE80::2AA:FF:FE22:2222

(multicast)

Ethernet Header: Dest. MAC is 33-33-00-00-00-01IPv6Header: Source Address is FE80::2AA:FF:FE22:2222 Destination address is FF02::1NA Header : Target Address is FE80::2AA:FF:FE22:2222

Outline IPv6 Overview Ad Hoc Networks IP Autoconfiguration CGA S-DSR Conclusion

What is a CGA

Cryptographically Generated Address Also known as SUCV

(Statistically Unique and Cryptographically Verifiable) address

It associates a host's address with its public key in order for other hosts to verify the ownership of the address

Public Key and a CGA

Outline IPv6 Overview Ad Hoc Networks IP Autoconfiguration CGA S-DSR Conclusion

S-DSR Overview (1/2) Secure Dynamic Source Routing Protocol It incorporates

DSR protocolCGAAddress autoconfigurationDNS autoregistration and discovery

S-DSR Overview (2/2) It allows the network to be bootstrapped

without manual administration It can resist a variety of attacks, including

black hole attackreplay attackmessage forging attackmessage tampering attackDNS impersonation attack

S-DSR Assumption There is a publicly known one-way, collision-resistant

hashing function H, and there exists an IPv6 DNS server in the MANET. The DNS server has a public-private key pair, which is known by all mobile nodes prior to entering the MANET.

For a mobile which intends to own a permanent domain name, an entry (domain name, IP address) should have been placed at the DNS server before the network is formed. In this case, impersonate such hosts would be impossible.

For a mobile node which dose not intend to own a permanent domain name, its (domain name, IP address) entry can be registered with the DNS server on-line after the network is formed. We adopt the first-come-first-serve policy for registration of new domain names.

S-DSR Messages (1/2)8 types of messages:

S-DSR Messages (2/2)Definitions of symbols:

S-DSR DAD (1/4) On receiving AREQ(SIP,seq,DN,ch,RR), each

intermediate node appends its address into the route record RR and rebroadcasts the message.

When a node R receives an AREQ with SIP equal to its own IP address, it unicasts an address reply message AREP(SIP,seq,RR, [SIP,seq,ch]RSK, RPK,Rrn) to S along the reverse route derived from RR.

S-DSR DAD (2/4) The AREP message should also be

delivered to the DNS server through unicast When a DNS server N receives the AREQ

message and finds that the domain name in the DN field has already been registered by another host of address different from SIP, it will also unicast a DREP message (SIP, seq,RR, [SIP,seq,ch]NSK) to S.

S-DSR DAD (3/4) When the node S with a pending address

request receives the AREP message, it authenticates the integrity of the message as follows:It verifies if SIP matches with H(RPK,Rrn).

It decrypts [SIP,seq,ch]RSK by RPK and verifies if the decrypted result matches with [SIP,seq,ch].

If both checks pass, the AREP message is considered valid.

S-DSR DAD (4/4)

S-DSR Routing (1/5) On receiving (SIP,DIP,seq,SRR,[SIP,DIP,seq]

SSK,SPK,Snd), each intermediate node I appends [SIP,seq]ISK,IIP,IPK,Irn into the secure route record SRR and rebroadcasts the message.

S-DSR Routing (2/5) On receiving RREQ (SIP,DIP,seq,SRR,

[SIP,DIP,seq] SSK,SPK,Snd), it authenticates the message as follows:

1. It verifies if SIP matches with H(SPk, Srn).

2. It decrypts [SIP,DIP,seq]SSK by SPK and verifies if the decrypted result matches with [SIP,DIP,seq] indicated in the message.

S-DSR Routing (3/5)3. It verifies every IP address appearing in SRR.

For an IP address IIP, whose corresponding information is [SIP,seq]ISK, IIP, IPK,Irn, the verification is done by checking if IIP matches with H(IPK,Irn), and if [SIP,seq]ISK can be decrypted by IPk to be [SIP,seq].

4. It verifies if seq is greater than the sequence number of any RREQ message sent by S.

S-DSR Routing (4/5) If all the verifications are passed, the

RREQ message is considered valid. The destination node D then unicasts a

RREP Message (SIP,DIP,seq,RR,SR(D-S), [SIP,seq,SR(D-S)]DSK,DPK,Drn) to S along source route SR(D-S), which is derived form SRR.

S-DSR Routing (5/5)

Outline IPv6 Overview Ad Hoc Networks IP Autoconfiguration CGA S-DSR Conclusion

Conclusion (1/2) S-DSR can resist

Black hole attackRoute request (RREQ) message reply attackForged route request (RREQ) message attackForged address reply (AREP) message attackForged route error (RERR) message attackTampered control message attacksDNS server impersonation attack

Conclusion (2/2)Future work:

To extend S-DSR to be a credit-based protocol with the help of CGAs, in which each node keeps a record for each IP address to differentiate between favorable nodes and unfavorable nodes.

Publication

Yu-Chee Tseng, Jehn-Ruey Jiang, and Jih-Hsin Lee, “Secure Bootstrapping and Routing in an IPv6-Based Ad Hoc Network,” ICPP Workshop on Wireless Security and Privacy 2003, 2003.

Yu-Chee Tseng, Jehn-Ruey Jiang*, and Jih-Hsin Lee, “Secure Bootstrapping and Routing in an IPv6-Based Ad Hoc Network,” Journal of Internet Technology, Vol. 5, No. 2, pp.123-130, Feb. 2004.

Q&A