Users (or software agents) are served by multiple networked terminal devices, each of which may in turn have multiple network interfaces. This multi-homing at both ???user??? and ???device??? level presents new opportunities for mobility handling. Mobility may be handled by switching ongoing application data streams between devices, by utilising intermediary adaptation or connectivity enhancement services, or both. However this requires middleware support that is not provided by current systems. This thesis presents a set of integrated solutions to enable this kind of mobility handling, based on concept of Personal Networks (PN). Personal Networks (PN) consist of dynamic conglomerations of terminal and service devices tasked to facilitate the delivery of information to and from a single focal point, which may be a human user or software agent. This concept creates the potential to view mobility handling as a path selection problem, since there may be multiple valid terminal device and service proxy configurations that can successfully carry a given communication session from one PN to another PN. Depending on context, it may be necessary to switch between paths. To this end, this thesis proposes and evaluates a set of inter-dependent mechanisms to facilitate the discovery and use of different candidate end-to-end paths. The proposal comprises mechanisms for secure inter-device mobility using delegated cryptographic identifiers, autonomous service proxy selection and composition, and distributed resolution of cryptographic identifiers to lower layer addresses.

Users (or software agents) are served by multiple networked terminal devices, each of which may in turn have multiple network interfaces. This multi-homing at both ???user??? and ???device??? level presents new opportunities for mobility handling. Mobility may be handled by switching ongoing application data streams between devices, by utilising intermediary adaptation or connectivity enhancement services, or both. However this requires middleware support that is not provided by current systems. This thesis presents a set of integrated solutions to enable this kind of mobility handling, based on concept of Personal Networks (PN). Personal Networks (PN) consist of dynamic conglomerations of terminal and service devices tasked to facilitate the delivery of information to and from a single focal point, which may be a human user or software agent. This concept creates the potential to view mobility handling as a path selection problem, since there may be multiple valid terminal device and service proxy configurations that can successfully carry a given communication session from one PN to another PN. Depending on context, it may be necessary to switch between paths. To this end, this thesis proposes and evaluates a set of inter-dependent mechanisms to facilitate the discovery and use of different candidate end-to-end paths. The proposal comprises mechanisms for secure inter-device mobility using delegated cryptographic identifiers, autonomous service proxy selection and composition, and distributed resolution of cryptographic identifiers to lower layer addresses.

Abstract Ethernet based VPLS (Virtual Private LAN Service) is a transparent, protocol independent, multipoint L2VPN (Layer 2 Virtual Private Network) mechanism to interconnect remote customer sites over IP (Internet Protocol) or MPLS (Multiprotocol Label Switching) based provider networks. VPLS networks are now becoming attractive in many Enterprise applications, such as DCI (data center interconnect), voice over IP (VoIP) and videoconferencing services due to their simple, protocol-independent and cost efficient operation. However, these new VPLS applications demand additional requirements, such as elevated security, enhanced scalability, optimum utilization of network resources and further reduction in operational costs. Hence, the motivation of this thesis is to develop secure and scalable VPLS architectures for future communication networks. First, a scalable secure flat-VPLS architecture is proposed based on a Host Identity Protocol (HIP). It contains a session key-based security mechanism and an efficient broadcast mechanism that increase the forwarding and security plane scalability of VPLS networks. Second, a secure hierarchical-VPLS architecture is proposed to achieve control plane scalability. A novel encrypted label-based secure frame forwarding mechanism is designed to transport L2 frames over a hierarchical VPLS network. Third, a novel Distributed Spanning Tree Protocol (DSTP) is designed to maintain a loop free Ethernet network over a VPLS network. With DSTP it is proposed to run a modified STP (Spanning Tree Protocol) instance in each remote segment of the VPLS network. In addition, two Redundancy Identification Mechanisms (RIMs) termed Customer Associated RIMs (CARIM) and Provider Associated RIMs (PARIM) are used to mitigate the impact of invisible loops in the provider network. Lastly, a novel SDN (Software Defined Networking) based VPLS (Soft-VPLS) architecture is designed to overcome tunnel management limitations in legacy secure VPLS architectures. Moreover, three new mechanisms are proposed to improve the performance of legacy tunnel management functions: 1) A dynamic tunnel establishment mechanism, 2) a tunnel resumption mechanism and 3) a fast transmission mechanism. The proposed architecture utilizes a centralized controller to command VPLS tunnel establishment based on real-time network behavior. Hence, the results of the thesis will help for more secure, scalable and efficient system design and development of VPLS networks. It will also help to optimize the utilization of network resources and further reduction in operational costs of future VPLS networks. / Tiivistelmä Ethernet-pohjainen VPLS (Virtual Private LAN Service) on läpinäkyvä, protokollasta riippumaton monipisteverkkomekanismi (Layer 2 Virtual Private Network, L2VPN), jolla yhdistetään asiakkaan etäkohteet IP (Internet Protocol)- tai MPLS (Multiprotocol Label Switching) -yhteyskäytäntöön pohjautuvien palveluntarjoajan verkkojen kautta. VPLS-verkoista on yksinkertaisen protokollasta riippumattoman ja kustannustehokkaan toimintatapansa ansiosta tullut kiinnostavia monien yrityssovellusten kannalta. Tällaisia sovelluksia ovat esimerkiksi DCI (Data Center Interconnect), VoIP (Voice over IP) ja videoneuvottelupalvelut. Uusilta VPLS-sovelluksilta vaaditaan kuitenkin uusia asioita, kuten parempaa tietoturvaa ja skaalautuvuutta, optimaalista verkkoresurssien hyödyntämistä ja käyttökustannusten pienentämistä entisestään. Tämän väitöskirjan tarkoituksena onkin kehittää turvallisia ja skaalautuvia VPLS-arkkitehtuureja tulevaisuuden tietoliikenneverkoille. Ensin väitöskirjassa esitellään skaalautuva ja turvallinen flat-VPLS-arkkitehtuuri, joka perustuu Host Identity Protocol (HIP) -protokollaan. Seuraavaksi käsitellään istuntoavaimiin perustuvaa tietoturvamekanismia ja tehokasta lähetysmekanismia, joka parantaa VPLS-verkkojen edelleenlähetyksen ja tietoturvatason skaalautuvuutta. Tämän jälkeen esitellään turvallinen, hierarkkinen VPLS-arkkitehtuuri, jolla saadaan aikaan ohjaustason skaalautuvuus. Väitöskirjassa kuvataan myös uusi salattu verkkotunnuksiin perustuva tietokehysten edelleenlähetysmekanismi, jolla L2-kehykset siirretään hierarkkisessa VPLS-verkossa. Lisäksi väitöskirjassa ehdotetaan uuden Distributed Spanning Tree Protocol (DSTP) -protokollan käyttämistä vapaan Ethernet-verkkosilmukan ylläpitämiseen VPLS-verkossa. DSTP:n avulla on mahdollista ajaa muokattu STP (Spanning Tree Protocol) -esiintymä jokaisessa VPLS-verkon etäsegmentissä. Väitöskirjassa esitetään myös kaksi Redundancy Identification Mechanism (RIM) -mekanismia, Customer Associated RIM (CARIM) ja Provider Associated RIM (PARIM), joilla pienennetään näkymättömien silmukoiden vaikutusta palveluntarjoajan verkossa. Viimeiseksi ehdotetaan uutta SDN (Software Defined Networking) -pohjaista VPLS-arkkitehtuuria (Soft-VPLS) vanhojen turvallisten VPLS-arkkitehtuurien tunnelinhallintaongelmien poistoon. Näiden lisäksi väitöskirjassa ehdotetaan kolmea uutta mekanismia, joilla voidaan parantaa vanhojen arkkitehtuurien tunnelinhallintatoimintoja: 1) dynaaminen tunnelinluontimekanismi, 2) tunnelin jatkomekanismi ja 3) nopea tiedonsiirtomekanismi. Ehdotetussa arkkitehtuurissa käytetään VPLS-tunnelin luomisen hallintaan keskitettyä ohjainta, joka perustuu reaaliaikaiseen verkon käyttäytymiseen. Tutkimuksen tulokset auttavat suunnittelemaan ja kehittämään turvallisempia, skaalautuvampia ja tehokkaampia VLPS järjestelmiä, sekä auttavat hyödyntämään tehokkaammin verkon resursseja ja madaltamaan verkon operatiivisia kustannuksia.

Au cours des dernières décennies, le besoin pour des communications multimédia en mobilité est devenu indéniable dans les réseaux de type IP, ainsi la gestion de la mobilité et la continuité de session est depuis plusieurs années un problème de recherche très important aussi bien pour le milieu académique qu’industriel. Comme l'hétérogénéité des réseaux d’accès est en perpétuelle évolution, l'intégration des différents types de réseaux sans fil au niveau de la couche IP est devenue un domaine de recherche difficile et inévitable. L'un des problèmes les plus importants liés à l'exécution de la gestion de la mobilité concerne le fait que la couche d'application souffre de la modification d'adresses IP au cours du mouvement du nœud mobile alors que celle-ci construit sa session sur la base de l’adresse IP de connexion au réseau. Une nouvelle approche d'amélioration de la prise en charge de la mobilité propose de séparer l'identification de session et l'identification de l’emplacement ou l’attachement au réseau. Donc, par la séparation de ces deux concepts, les sessions ne sont pas identifiés par les adresses IP qui elles sont dynamiques puisque la mobilité dans le réseau impose le changement d’adresse IP, mais les nouveaux identificateurs uniques qui définissent un nœud et qui ne change pas à cause de la mobilité ce qui offrirait une stabilité pour le niveau applicatif. Selon ces concepts, Host Identity Protocol (HIP) est l'une des solutions dominantes en recherches qui est proposé par l'IETF et l’IRTF. Dans cette thèse, le protocole HIP est principalement examiné et de nouvelles améliorations de la mobilité sur la base de ce protocole ont été conçues et mises en place / Over the last decades, with rapid and tremendous growth of IP networks in mobile and wireless environments, mobility management and session continuity has become a more important issue. As the heterogeneity increases in network environments and gradual spread of Internet of Things wave, the integration of different types of wireless networks in the IP layer became a challenging and inevitable research area. One of the most important issues related to mobility management is related to the fact that the application layer suffers from the changing of IP addresses during the movement of the mobile node. It is expected the network layer and above layers to be aware of movement of mobile nodes. New wave in the improvement ideas on this concept is separating the session identification and the location identification. This avoids the applications to suffer when the IP address changes during the mobility. This new approach needs to introduce a new layer in the TCP/IP protocol stack, on top of the IP layer that will handle the new identifiers correspondent with the current IP address or new complete architecture designs which are inheriting locator/identifier separation idea. According to these concepts, Host Identity Protocol (HIP) is one of the dominant and prominent researches that is proposed by IETF and IRTF. This protocol proposes to solve the locator/identifier split problem by also including the security support. In this thesis, predominantly HIP protocol is examined and new mobility enhancements based on this protocol have been designed and introduced

Newly implemented technologies within the aviation lack, according to recent studies, built in security measures to protect them against outside interference. In this thesis we study the security and privacy status of the digital wireless Controller Pilot Data Link Communication (CPDLC) used in air traffic management alongside other systems to increase the safety and traffic capacity of controlled airspaces. The findings show that CPDCL is currently insecure and exposed to attacks. Any solutions to remedy this must adhere to its low levels of performance. Elliptical Curve Cryptography, Protected ACARS and Host Identity Protocol have been identified as valid solutions to the system’s security drawbacks and all three are possible to implement in the present state of CPDLC.

Denial-of-service attacks (DoS) and distributed denial-of-service attacks (DDoS) attempt to temporarily disrupt users or computer resources to cause service un- availability to legitimate users in the internetworking system. The most common type of DoS attack occurs when adversaries °ood a large amount of bogus data to interfere or disrupt the service on the server. The attack can be either a single-source attack, which originates at only one host, or a multi-source attack, in which multiple hosts coordinate to °ood a large number of packets to the server. Cryptographic mechanisms in authentication schemes are an example ap- proach to help the server to validate malicious tra±c. Since authentication in key establishment protocols requires the veri¯er to spend some resources before successfully detecting the bogus messages, adversaries might be able to exploit this °aw to mount an attack to overwhelm the server resources. The attacker is able to perform this kind of attack because many key establishment protocols incorporate strong authentication at the beginning phase before they can iden- tify the attacks. This is an example of DoS threats in most key establishment protocols because they have been implemented to support con¯dentiality and data integrity, but do not carefully consider other security objectives, such as availability. The main objective of this research is to design denial-of-service resistant mechanisms in key establishment protocols. In particular, we focus on the design of cryptographic protocols related to key establishment protocols that implement client puzzles to protect the server against resource exhaustion attacks. Another objective is to extend formal analysis techniques to include DoS- resistance. Basically, the formal analysis approach is used not only to analyse and verify the security of a cryptographic scheme carefully but also to help in the design stage of new protocols with a high level of security guarantee. In this research, we focus on an analysis technique of Meadows' cost-based framework, and we implement DoS-resistant model using Coloured Petri Nets. Meadows' cost-based framework is directly proposed to assess denial-of-service vulnerabil- ities in the cryptographic protocols using mathematical proof, while Coloured Petri Nets is used to model and verify the communication protocols using inter- active simulations. In addition, Coloured Petri Nets are able to help the protocol designer to clarify and reduce some inconsistency of the protocol speci¯cation. Therefore, the second objective of this research is to explore vulnerabilities in existing DoS-resistant protocols, as well as extend a formal analysis approach to our new framework for improving DoS-resistance and evaluating the performance of the new proposed mechanism. In summary, the speci¯c outcomes of this research include following results; 1. A taxonomy of denial-of-service resistant strategies and techniques used in key establishment protocols; 2. A critical analysis of existing DoS-resistant key exchange and key estab- lishment protocols; 3. An implementation of Meadows's cost-based framework using Coloured Petri Nets for modelling and evaluating DoS-resistant protocols; and 4. A development of new e±cient and practical DoS-resistant mechanisms to improve the resistance to denial-of-service attacks in key establishment protocols.

Abstract Software-Defined Networks (SDN) focus on addressing the challenges of increased complexity and unified communication, for which the conventional networks are not optimally suited due to their static architecture. This dissertation discusses the methods about how to enhance communication security and mobility management in small-cell networks with IEEE 802.11 backhaul. Although 802.11 has become a mission-critical component of enterprise networks, in many cases it is not managed with the same rigor as the wired networks. 802.11 networks are thus in need of undergoing the same unified management as the wired networks. This dissertation also addresses several new issues from the perspective of mobility management in 802.11 backhaul. Due to lack of built-in quality of service support, IEEE 802.11 experiences serious challenges in meeting the demands of modern services and applications. 802.11 networks require significantly longer duration in association compared to what the real-time applications can tolerate. To optimise host mobility in IEEE 802.11, an extension to the initial authentication is provided by utilising Host Identity Protocol (HIP) based identity attributes and Elliptic Curve Cryptography (ECC) based session key generation. Finally, this dissertation puts forward the concept of SDN based cell mobility and network function virtualization, its counterpart. This is validated by introducing a unified SDN and cognitive radio architecture for harmonized end-to-end resource allocation and management presented at the end. / Tiivistelmä Ohjelmisto-ohjatut verkot (SDN) keskittyvät ratkaisemaan haasteita liittyen kasvaneeseen verkkojen monimutkaisuuteen ja yhtenäiseen kommunikaatioon, mihin perinteiset verkot eivät staattisen rakenteensa vuoksi sovellu. Väitöskirja käsittelee menetelmiä, joilla kommunikaation turvallisuutta ja liikkuvuuden hallintaa voidaan parantaa IEEE 802.11 langattomissa piensoluverkoissa. Vaikkakin 802.11 on muodostunut avainkomponentiksi yritysverkoissa, monissa tapauksissa sitä ei hallinnoida yhtä täsmällisesti kuin langallista verkkoa. 802.11 verkoissa on näin ollen tarve samantyyppiselle yhtenäiselle hallinnalle, kuin langallisissa verkoissa on. Väitöskirja keskittyy myös moniin uusiin liikkuvuuden hallintaan liittyviin ongelmiin 802.11 verkoissa. Johtuen sisäänrakennetun yhteyden laatumäärittelyn (QoS) puuttumisesta, IEEE 802.11 verkoille on haasteellista vastata modernien palvelujen ja sovellusten vaatimuksiin. 802.11 verkot vaativat huomattavasti pidemmän ajan verkkoon liittymisessä, kuin reaaliaikasovellukset vaativat. Työssä on esitelty laajennus alustavalle varmennukselle IEEE 802.11-standardiin isäntälaitteen liikkuvuuden optimoimiseksi, joka hyödyntää Host Identity Protocol (HIP)-pohjaisia identiteettiominaisuuksia sekä elliptisten käyrien salausmenetelmiin (ECC) perustuvaa istunnon avaimen luontia. Lopuksi työssä esitellään ohjelmisto-ohjattuihin verkkoihin pohjautuva solujen liikkuvuuden konsepti, sekä siihen olennaisesti liittyvä verkon virtualisointi. Tämä validoidaan esittelemällä yhtenäinen SDN:ään ja kognitiiviseen radioon perustuva arkkitehtuuri harmonisoidulle päästä päähän resurssien varaamiselle ja hallinnoinnille, joka esitellään lopussa.

Secret sharing is critical to most applications making use of security and remains one of the most challenging research areas in modern cryptography. In this thesis, we propose a novel efficient multi-secret sharing scheme based on the Chinese remainder theorem (CRT) with two verification methods, while the previous works are mostly based on the Lagrange polynomial. Key management schemes play an important role in communication security in Wireless Sensor Networks (WSNs). While the previous works mainly targeting on two different types of WSNs: distributed and hieratical, in this thesis, we propose our flexible WSN key management scheme, which is based on (n,t,n) multi-secret sharing technique, to provide a key management solution for heterogeneous architecture. The powerful key managers are responsible for most of the communicational and computational workload. They can provide Peer-to-Peer pair-wise keys for a pair of sensors to establish a secure communication session, and in the same time, they can also form communication clusters as cluster heads according to different application requirements. Internet of Things (IoT) becomes more and more popular and practical in recent years. Considering the diversity of the devices and the application scenarios, it is extremely hard to couple two devices or sub-networks with different communication and computation resources. In this thesis, we propose novel key agreement schemes based on (n,t,n) multi-secret sharing techniques for IoT in order to achieve light weighted key exchange while using Host Identity Protocol (HIP). We refer the new schemes as HIP-MEXs with different underlying multi-secret sharing techniques. We analyzed the computational and communication costs of the extremely resource constrained device which is referred to as Initiator, and CRT based HIP-MEX successfully outsource the heavy workload to the proxy, which are considered more powerful, when establishing new secret key.

Wireless networking introduces a whole range of challenges to the traditional TCP/IP network. In particular, IP address the issue of overloading because IP addresses are used as a network locator and an end point identity in the different layers in an OSI model. Even though Mobile IP is widely deployed, it has significant problems relating to performance and security. The Host Identity Protocol (HIP) provides secure mobility management by solving the IP address overloading from another angle. It restructures the TCP/IP model and introduces a new layer and a new namespace. The performance of HIP has proven to be better than Mobile IP and also opens a range of new research opportunities. This dissertation proposes and analyses a new step-stone solution from the Mobile IP-based network into a HIP-based network. The main advantage of this new solution is that much less change is required to the operating system kernel of the end point compared to a full HIP implementation. The new step-stone solution allows Mobile IP to use some HIP features to provide better security and handover performance. This dissertation also proposes several new and novel HIP-based wireless communication network architectures. An HIP-based heterogeneous wireless network architecture and handover scheme has been proposed and analysed. These schemes limit the HIP signalling in the wireless network if no communication to external networks is needed. Beside the network architecture modification, the hybrid Session Initial Protocol (SIP) and HIP-based Voice over IP (VoIP) scheme is proposed and analysed. This novel scheme improves the handover latency and security. This dissertation also proposes and analyses a new and novel extension to HIP, a HIP-based micro-mobility management, micro-HIP (mHIP). mHIP provides a new secure framework for micro-mobility management. It is a more complete HIP-based micro-mobility solution than any other proposed in existing studies. mHIP improves the intra-domain handover performance, the security, and the distribution of load in the intra-domain handover signalling. The new work presented opens up a number of very interesting research opportunities.

Abstract The concept of the Internet of Things (IoT) is driven by advancements of the Internet with the interconnection of heterogeneous smart objects using different networking and communication technologies. Among many underlying networking technologies for the IoT, Wireless Sensor Network (WSN) technology has become an integral building block. IoT enabled sensor networks provide a wide range of application areas such as smart homes, connected healthcare, smart cities and various solutions for the manufacturing industry. The integration of WSNs in IoT will also create new security challenges for establishing secure channels between low power sensor nodes and Internet hosts. This will lead to many challenges in designing new key establishment and authentication protocols and redefining the existing ones. This dissertation addresses how to integrate lightweight key management and authentication solutions in the resource constrained sensor networks deployed in IoT domains. Firstly, this thesis elaborates how to exploit the implicit certificates to initiate secure End-to-End (E2E) communication channels between the resource constrained sensor nodes in IoT networks. Implicit certificates are used for authentication and key establishment purposes. The compliance of the security schemes is proven through performance evaluations and by discussing the security properties. Secondly, this dissertation presents the design of two lightweight group key establishment protocols for securing group communications between resource-constrained IoT devices. Finally, the thesis explores promising approaches on how to tailor the existing security protocols in accordance with IoT device and network characteristics. In particular, variants of Host Identity Protocol (HIP) are adopted for constructing dynamic and secure E2E connections between the heterogeneous network devices with imbalanced resource profiles and less or no previous knowledge about each other. A solutions called Collaborative HIP (CHIP) is proposed with an efficient key establishment component for the high resource-constrained devices on the IoT. The applicability of the keying mechanism is demonstrated with the implementation and the performance measurements results. / Tiivistelmä Esineiden internet (IoT) on viime aikoina yleistynyt konsepti älykkäiden objektien (smart objects) liittämiseksi internetiin käyttämällä erilaisia verkko- ja kommunikaatioteknologioita. Olennaisimpia esineiden internetin pohjalla toimivia teknologioita ovat langattomat sensoriverkot (WSN), jotka ovat esineiden internetin perusrakennuspalikoita. Esineiden internetiin kytketyt langattomat sensoriverkot mahdollistavat laajan joukon erilaisia sovelluksia, kuten älykodit, etäterveydenhuollon, älykkäät kaupungit sekä älykkäät teollisuuden sovellukset. Langattomien sensoriverkkojen ja esineiden internetin yhdistäminen tuo mukanaan myös tietoturvaan liittyviä haasteita, sillä laskentateholtaan yleensä heikot anturit ja toimilaitteet eivät kykene kovin vaativiin tietoturvaoperaatioihin, joihin lukeutuvat mm. tietoturva-avaimen muodostus ja käyttäjäntunnistus. Tässä väitöskirjassa pyritään vastaamaan haasteeseen käyttämällä kevyitä avaimenmuodostus- ja käyttäjäntunnistusratkaisuja esineiden internetiin kytketyissä resurssirajoitetuissa sensoriverkoissa. Väitöstutkimuksessa keskitytään aluksi implisiittisten sertifikaattien käyttöön tietoturvallisten end-to-end-kommunikaatiokanavien alustamisessa resurssirajoitettujen sensori- ja muiden IoT-laitteiden välillä. Implisiittisiä sertifikaatteja käytetään käyttäjäntunnistuksessa sekä avaimenmuodostuksessa. Kehitettyjen ratkaisujen soveltuvuus tarkoitukseen osoitetaan suorituskykymittauksilla sekä vertaamalla niiden tietoturvaomi- naisuuksia. Seuraavaksi väitöskirjassa esitellään kaksi kevyttä ryhmäavaimenmuodostus- protokollaa tietoturvalliseen ryhmäkommunikaatioon resurssirajoitettujen IoT-laitteiden välillä. Lopuksi väitöskirjassa tarkastellaan lupaavia lähestymistapoja olemassa olevien tietoturvaprotokollien räätäläintiin IoT-laitteiden ja -verkkojen ominaisuuksille sopiviksi. Erityistä huomiota kiinnitetään Host Identity -protokollan (HIP) eri versioiden käyttöön dynaamisten ja tietoturvallisten end-to-end-yhteyksien luomiseen toisilleen ennestään tuntemattomien erityyppisten IoT-laitteiden välillä, joiden laitteistoresurssiprofiilit voivat olla hyvin erilaiset. Väitöskirjan keskeinen tulos on väitöskirjatyössä kehitetty Colla- borative HIP (CHIP) -protokolla, joka on resurssitehokas avaimenmuodostusteknologia resurssirajoitetuille IoT-laitteille. Kehitetyn teknologian soveltuvuutta tarkoitukseensa demonstroidaan prototyyppitoteutuksella tehtyjen suorituskykymittausten avulla.