Secure Mobile IP CommunicationIntroductionOverview of Mobile IPMobile IP FunctionalitiesAgent Discovery and RegistrationSlide 6Slide 7Slide 8Slide 9Security issues in Mobile IPSecurity ModelsSlide 12The Solution: IPSecWhat is IPSec?How it works? The ProtocolIPSec ModesEncapsulating Security PayloadAuthentication HeaderInternet Key ExchangeDiffie- Hellman SchemeSecure Mobile IP ScenarioIPSec in Mobile IPSec Mobile IP OperationNetwork DetectionAcquiring a routable IP addressBi-directional IPSec tunnelRegistration and Data TransferMessages ExchangedSlide 29Slide 30Security Aspects using SecMIPExperimental ResultsNetwork PerformanceMobile IPSecMIPConclusionSecure Mobile IP CommunicationMarc Danzeisen andProf. Dr. Torsten BraunInstitute of Computer Science and Applied Mathematics, University of BernPresented By, Vinod MehtaIntroduction•Describes a solution called Secure Mobile IP (SecMIP) to provide mobile IP users secure access to their company's firewall protected virtual private network.•The solution requires neither introducing new protocols nor to insert or modify network components. It only requires a slight adaptation of the end system communication software. •The paper describes the concept, prototype implementation, and initial performance measurement results.Overview of Mobile IP•Mobile Node (MN): A host or router, which can change its point of attachment from one network or sub network to another. This change of location may not concern its (home) IP address. All ongoing communications can be maintained without any interrupt.•Home Agent (HA): A router on the mobile node’s home network that redirects any IP packets for the mobile node to its current location.•Foreign Agent (FA): A router on a visited network providing routing services to the MN.•Correspondent Node (CN): A host or a router with which MN wants to communicate.Mobile IP Functionalities•Agent Discovery•Registration•TunnelingAgent Discovery and RegistrationFA DecapsulationMN DecapsulationIngress Filtering could be a problem.Triangle RoutingOptimization can be achieved by directly FA routing the packets between MN and CN by building a tunnel with CN.Reverse Tunneling• Security will be a problem• Have to inform all the CN of the MN’s COA– Not very feasibleOptimized RoutingSecurity issues in Mobile IP•Eavesdropping: Where the attacker is simply “listening” at the communication with some IP packet sniffer software.•Replay Attack: An attacker records and replays the registration sequence later.•Denial of Service: An attacker overflows access server. This is possible because the sensitive IP addresses of the HA and the MN are not hidden in the registration messages.•Tunnel Spoofing: The tunnel to the home network may be used to hide malicious IP packets and get them pass the firewall.•Session Stealing: Attacker hi-jacks session just after registration.Security Models•Weak Security ApproachHA has confidence that the care-of address of a MN is correct, because all allowed care-of addresses concern to well known IP address ranges in the campus network.Foreign Mobile IP compatible nodes (guests) in the network need to authenticate bindings.When a MN is migrating outside the protected campus network, it sends a registration request with password to the HA.•Strong Security ApproachMobile IP authenticates any binding notification messages or other information received about a mobile host.Public and private keys and trusted servers are used, but in turn it slows down the operationAll these open issues make it hard to deploy Mobile IP in a company’s network environment that is used to transfer sensitive data.What is the solution to this?IPSec can solve nearly all of these security problems.The Solution: IPSec•What is IPsec?•How does it work?•What issues does it handle?What is IPSec?•It’s a method developed by IETF to secure IP layer.•This protocol suite adds security services to the IP layer keeping compatible with IP standard.•IPSec eases building secure virtual private networks (VPN) – a secure, private network that is as safe or safer than an isolated office LAN, but built on an unsecured, public network.How it works? The ProtocolThe IPSec-Protocol-Suite consists of three main parts:• Authentication Header (AH) - ties data in each packet to a verifiable signature that allows to verify both the identity of the person sending data and that data has not been modified.• Encapsulating Security Payload (ESP) – encrypts data (and even certain sensitive IP addresses) in each packet – so a sniffer somewhere on the network doesn’t get anything usable.• Internet Key Exchange (IKE) – a powerful, flexible negotiation protocol that allows users to agree on authentication methods, encryption methods, the keys to use, how long to use the keys before changing them, and that allows smart, secure key exchange.IPSec Modes•Transport•TunnelEncapsulating Security PayloadComponents•Security AssociationBased on the rules of that SA, decide how to decrypt and authenticate the received data.• SPI- Security Parameter Index• Sequence NumberAuthentication Header•As its name says, it offers just authentication of data and not confidentiality.•IPSec uses symmetric encryption scheme to encrypt the transported data.•So now the only problem is to ensure a confidential exchange of this shared key among the communicating parties.Internet Key Exchange•IPSec group’s answer to protocol negotiation and key exchange through the Internet.•Works in two phases :–Phase 1 has 2 modes•Main mode•Aggressive mode–Phase 2 has just 1 mode•Quick Mode-accomplishes by negotiating an SA for general purpose communications.Diffie- Hellman Scheme•The keys are exchanged by Diffie Hellman scheme.•Consider 2 parties A and B. Both select a large prime number P and a primitive g. These are not secret.•A selects a large prime number x (x<P) and transmits to BX=g x mod P•B selects a large prime number y (y<P) and transmits to AY=g y mod P•A calculates the remainder s =Y x mod P•B calculates the remainder s’ =X y mod P•Now s = s’ =g xy mod P•No one else can come up with this value with just knowing X,Y,P,g•They need to know either x or y since the value s or s’ depends on the private key which is secret.Secure Mobile IP Scenario•Demilitarized Zone (DMZ)•MVPNIPSec in Mobile IP•As the mobile nodes that belong to the corporation have to traverse the