Group communication, security and 5G technology present a unique dimension of challenges and security remains crucial in the successful deployment of 5G technology across different industry. Group key management plays a vital role in secure group communication. This research work studies various group key management schemes for mobile wireless technology and then a new scheme is proposed and evaluated. The main architecture is analysed, while the components and their roles are established, trust and keying relationships are evaluated, as well as detailed functional requirements. A detailed description of the main protocols required within the scheme is also described. A numerical and simulation analysis is employed to assess the proposed scheme with regards to fulfilling the security requirement and performance requirements. The impact of group size variation, the impact of mobility rate variation are studied with regards to the average rekeying messages induced by each event and 1-affects-n phenomenon. The results obtained from the simulation experiments show that the proposed scheme outperformed other solutions with a minimal number of rekeying messages sent and less number of affected members on each event. The security requirements demonstrate that backward and forward secrecy is preserved and maintained during mobility between areas. Finally, the research work also proposes a 5G-enabled software-defined multicast network (5G-SDMNs), where software-defined networking (SDN) is exploited to dynamically manage multicast groups in 5G and mobile multicast environment. Also, mobile edge computing (MEC) is exploited to strengthen network control of 5G-SDMN. / National Open University of Nigeria

The Internet of Things has become the next big step of a general Internetevolution, and conveys the assurance of security as one of the biggest challenge.In particular, use cases and application scenarios that adopt groupcommunication schemes need to be properly secured, in order to protect themessage exchange among group members from a number of security attacks.A typical way to achieve secure group communication relies on the adoptionof a symmetric group key shared among all the group members. This in turnrequires to rely on a group key management scheme, which is responsible forrevoking and renewing the group key when nodes join or leave the group.Due to the resource-constrained nature of typical IoT devices, the adoptedgroup key management scheme should be ecient and highly scalable withthe group size.This thesis project has been conducted in collaboration with SICS SwedishICT, a research institute with focus on applied computer science. We haveimplemented an ecient group key management protocol initially proposedand designed by SICS, considering the Contiki operating system and resourceconstrainedIoT platforms. We have also experimentally evaluated the protocolin terms of storage overhead, communication overhead, energy consumptionand total required rekeying time. / Internet of Things har blivit nästa stora steg i en generell utveckling avInternet, där en av de största utmaningarna är att garantera säkerhet.Speciellt användningsfall och applikationsscenarion som använder metoderför gruppkommunikation måste vara ordentligt säkrade, för att kunna skyddautbyte av meddelanden mellan gruppens medlemmar från ett antal attackscenarion.Ett vanligt sätt att uppnå säker gruppkommunikation baseras på användningav en symmetrisk gruppnyckel som delas av alla gruppens medlemmar.Detta i sin tur gör det nödvändigt att förlita sig på ett system för hanteringav gruppnycklar, vilket är ansvarigt för återkallning och förnyelse av nycklarnär noder går med i eller lämnar gruppen.På grund av att typiska IoT enheter har begränsade resurser måste metodensom används för hantering av gruppnycklar vara eektiv och mycketskalbar med gruppstorleken.Denna masteruppsats har utförts i samarbetet med SICS Swedish ICT,ett forskningsinstitut med fokus på applicerad datavetenskap. Vi har implementeratett eektiv protokoll för hantering av gruppnycklar ursprungligenframtaget och designat av SICS, med operativsystemet Contiki och resursbegränsade IoT-plattformar i åtanke. Vi har också experimentellt utvärderatprotokollet med hänsyn till overhead för datalagring, overhead för kommunikation,energikonsumtion och den totala tiden som krävs för förnyelse avnycklar.

No / The Versatile and Ubiquitous Secret Sharing System, a cloud data repository secure access and a web based authentication scheme. It is designed to implement the sharing, distribution and reconstruction of sensitive secret data that could compromise the functioning of an organisation, if leaked to unauthorised persons. This is carried out in a secure web environment, globally. It is a threshold secret sharing scheme, designed to extend the human trust security perimeter. The system could be adapted to serve as a cloud data repository and secure data communication scheme. A secret sharing scheme is a method by which a dealer distributes shares of a secret data to trustees, such that only authorised subsets of the trustees can reconstruct the secret. This paper gives a brief summary of the layout and functions of a 15-page secure server-based website prototype; the main focus of a PhD research effort titled ‘Cryptography and Computer Communications Security: Extending the Human Security Perimeter through a Web of Trust’. The prototype, which has been successfully tested, has globalised the distribution and reconstruction processes. / Petroleum Technology Development Fund

A distributed application may be considered as a set of nodes which are spread across the network, and need to communicate with each other. The design and implementation of these distributed applications is greatly simplified using Group Communication Systems (GCSs) which provide multipoint to multipoint communication. Hence, GCSs can be used as building blocks for implementing distributed applications. The GCS is responsible for reliable delivery of group messages and management of group membership. The peer-to-peer model and the client-server model are the two models of distributed systems for implementing GCSs. In this thesis, our focus is on improving the capability of GCS based on the client-server model. Security is an important requirement of many distributed applications. For such applications, security has to be provided m the GCS itself. The security of a GCS includes confidentiality, authentication and non-repudiation of messages, and ensuring that the GCS is properly meeting its guarantees. The complexity and cost of implementation of the above three types of security guarantees greatly depend on whether the GCS servers are trusted by the group members or not. Making use of the GCS services provided by untrusted GCS servers becomes necessary when the GCS servers are managed by a third party. In this thesis, we have proposed algorithms for ensuring the above three security guarantees for GCSs in which servers are not trusted. As part of the solution, we have proposed a new digital multisignature scheme which allows group members to verify that a message has indeed been signed by all group members. The various group key management algorithms proposed in literature differ from each other with respect to the following four metrics: communication overhead, computational overhead, storage at each member and distribution of load among group members. We identify the need for a distributed group key management algorithm which minimizes the computational overhead on group members and propose an algorithm to achieve it.

Secure information exchanges over cyberspace is on the increase due to the convergence of wireless and mobile access technologies in all businesses. Accordingly, with the proliferation of diverse multicast group service subscriptions that are possible to co-exist within a single broadband network, there is also huge demand by the mobile subscribers to ubiquitously access these services over high speed broadband using their portable devices. Likewise, the Network Providers (NPs) invest hugely in infrastructure deployment to disseminate these services efficiently and concomitantly. Therefore, cyber security in any business is obligatory to restrict access of disseminated services to only authorised personnel. This becomes a vital requirement for a successful commercialisation of exchanged group services. The standard way to achieve cyber security in a wireless mobile multicast communication environment is through confidentiality using Group Key Management (GKM).The existing GKM schemes for secure wireless multicast from literature only target single group service confidentiality; however, the adoption of multiple group service confidentiality in them involve inefficient management of keys that induce huge performance overheads unbearable for real time computing. Therefore, a novel authenticated GKM scheme for multiple multicast group subscriptions known as slot based multiple group key management (SMGKM) is proposed. In the SMGKM, the handovers move across diverse decentralised clusters of homogeneous or heterogeneous wireless access network technologies while participating in multiple group service subscriptions. Unlike the conventional art, the SMGKM advances its security by integrating location based authentication and GKM functions. Both functions are securely offloaded from the Domain Key Distributor (DKD) to the intermediate cluster controllers, Area Key Distributors (AKDs), in a distributed fashion, using the proposed location based authenticated membership list (SKDL). A significant upgrade of fast handoff performance with reduced performance overheads of the SMGKM scheme is achieved. The developed numerical analysis and the simulation results display significant resource economy in terms of reduced rekeying transmission, communication bandwidth and storage overheads while providing enhanced security. The performance of the SMGKM in a high speed environment is also evaluated and has demonstrated that SMGKM outperforms the previous work. Finally, the SMGKM correctness against various attacks is verified using BAN logic, the eminent tool for analysing the widely deployed security protocols. The security analysis demonstrates that SMGKM can counteract the security flaws and redundancies identified in the chosen related art.

Les réseaux de capteurs sans fil (RCSF) sont devenus un thème porteur aussi bien pour la recherche académique que pour les activités des services de R&D en raison de leur simplicité de déploiement et de leur potentiel applicatif dans des domaines très variés (militaire, environnemental, industriel). Un RCSF est composé d'un ensemble de noeuds devant être opérationnels et autonomes énergétiquement pour de longues périodes. De ce fait ils sont limités en capacité mémoire et de calcul, et contraint à exploiter une faible puissance de transmission, ce qui en limite leur portée et rend leur débit modeste. Le besoin de sécuriser les communications dans un RCSF dépend de la criticité des données échangées pour l'application supportée. La solution doit reposer sur des échanges sûrs, confidentiels et fiables. Pour assurer la sécurisation des échanges, des techniques de cryptographie existent dans la littérature. Conçues à l'origine pour des réseaux informatiques majoritairement câblés, elles se basent généralement sur des algorithmes complexes et gourmands en ressource. Dans le cadre de cette thèse, nous avons proposé, implémenté et évalué une architecture sécurisée et dynamique adaptée aux communications des RCSF. Elle permet de garantir et de maintenir la sécurité des communications durant toute la durée de vie d'un réseau multi-saut. Nous avons utilisé et adapté des algorithmes standards de cryptographie, tels que AES-CTR et la suite d'algorithmes basée sur ECC, qui permettent à notre architecture de résister à la majorité d'attaques. Nous avons quantifié le surcoût en temps de calcul et en occupation mémoire de notre solution. Les résultats d’implémentation de notre proposition sont issus de mesures réelles faites sur une maquette réalisée à partir de cartes TelosB. / Wireless sensor networks (WSNs) have become an attractive topic for both academic research and the activity of R&D services due to their simple deployment and their potential of application in varied fields (military, environmental, industrial). A WSN is composed of a set of nodes that are supposed to operate and to be energetically autonomous for long durations. Thus, they are limited in memory and computing capacities, and constrained to function in a low-power transmission mode which limit their communication range and leave them with low data rates.The need to secure communications in a WSN depends on the criticality of the exchanged data for the supported application. The solution must be based on safe, confidential and reliable exchanges. To ensure the security of exchanges, cryptographic techniques exist in the literature. Originally designed for mostly wired computer networks, they are usually based on complex and resource-consuming algorithms. In this thesis, we have proposed, implemented and evaluated a secure and dynamic architecture suitable for WSNs communications. It ensures and maintains secured communications throughout the lifetime of a multi-hop network. We have used and adapted standard cryptographic algorithms, such as AES-CTR and algorithms based on ECC cipher suites, which allow our architecture to resist against most attacks. We have quantified the overhead of our solution in terms of computation time and memory occupancy. The results of implementation of our proposal are obtained through real measurements on testbeds using TelosB motes.

Les architectures des processeurs et coprocesseurs cryptographiques se montrent fréquemment vulnérables aux différents types d’attaques ; en particulier, celles qui ciblent une révélation des clés chiffrées. Il est bien connu qu’une manipulation des clés confidentielles comme des données standards par un processeur peut être considérée comme une menace. Ceci a lieu par exemple lors d’un changement du code logiciel (malintentionné ou involontaire) qui peut provoquer que la clé confidentielle sorte en clair de la zone sécurisée. En conséquence, la sécurité de tout le système serait irréparablement menacée. L’objectif que nous nous sommes fixé dans le travail présenté, était la recherche d’architectures matérielles reconfigurables qui peuvent fournir une sécurité élevée des clés confidentielles pendant leur génération, leur enregistrement et leur échanges en implantant des modes cryptographiques de clés symétriques et des protocoles. La première partie de ce travail est destinée à introduire les connaissances de base de la cryptographie appliquée ainsi que de l’électronique pour assurer une bonne compréhension des chapitres suivants. Deuxièmement, nous présentons un état de l’art des menaces sur la confidentialité des clés secrètes dans le cas où ces dernières sont stockées et traitées dans un système embarqué. Pour lutter contre les menaces mentionnées, nous proposons alors de nouvelles règles au niveau du design de l’architecture qui peuvent augmenter la résistance des processeurs et coprocesseurs cryptographiques contre les attaques logicielles. Ces règles prévoient une séparation des registres dédiés à l’enregistrement de clés et ceux dédiés à l’enregistrement de données : nous proposons de diviser le système en zones : de données, du chiffreur et des clés et à isoler ces zones les unes des autres au niveau du protocole, du système, de l’architecture et au niveau physique. Ensuite, nous présentons un nouveau crypto-processeur intitulé HCrypt, qui intègre ces règles de séparation et qui assure ainsi une gestion sécurisée des clés. Mises à part les instructions relatives à la gestion sécurisée de clés, quelques instructions supplémentaires sont dédiées à une réalisation simple des modes de chiffrement et des protocoles cryptographiques. Dans les chapitres suivants, nous explicitons le fait que les règles de séparation suggérées, peuvent également être étendues à l’architecture d’un processeur généraliste et coprocesseur. Nous proposons ainsi un crypto-coprocesseur sécurisé qui est en mesure d’être utilisé en relation avec d’autres processeurs généralistes. Afin de démontrer sa flexibilité, le crypto-coprocesseur est interconnecté avec les processeurs soft-cores de NIOS II, de MicroBlaze et de Cortex M1. Par la suite, la résistance du crypto-processeur par rapport aux attaques DPA est testée. Sur la base de ces analyses, l’architecture du processeur HCrypt est modifiée afin de simplifier sa protection contre les attaques par canaux cachés (SCA) et les attaques par injection de fautes (FIA). Nous expliquons aussi le fait qu’une réorganisation des blocs au niveau macroarchitecture du processeur HCrypt, augmente la résistance du nouveau processeur HCrypt2 par rapport aux attaques de type DPA et FIA. Nous étudions ensuite les possibilités pour pouvoir reconfigurer dynamiquement les parties sélectionnées de l’architecture du processeur – crypto-coprocesseur. La reconfiguration dynamique peut être très utile lorsque l’algorithme de chiffrement ou ses implantations doivent être changés en raison de l’apparition d’une vulnérabilité Finalement, la dernière partie de ces travaux de thèse, est destinée à l’exécution des tests de fonctionnalité et des optimisations stricts des deux versions du cryptoprocesseur HCrypt / Architectures of cryptographic processors and coprocessors are often vulnerable to different kinds of attacks, especially those targeting the disclosure of encryption keys. It is well known that manipulating confidential keys by the processor as ordinary data can represent a threat: a change in the program code (malicious or unintentional) can cause the unencrypted confidential key to leave the security area. This way, the security of the whole system would be irrecoverably compromised. The aim of our work was to search for flexible and reconfigurable hardware architectures, which can provide high security of confidential keys during their generation, storage and exchange while implementing common symmetric key cryptographic modes and protocols. In the first part of the manuscript, we introduce the bases of applied cryptography and of reconfigurable computing that are necessary for better understanding of the work. Second, we present threats to security of confidential keys when stored and processed within an embedded system. To counteract these threats, novel design rules increasing robustness of cryptographic processors and coprocessors against software attacks are presented. The rules suggest separating registers dedicated to key storage from those dedicated to data storage: we propose to partition the system into the data, cipher and key zone and to isolate the zones from each other at protocol, system, architectural and physical levels. Next, we present a novel HCrypt crypto-processor complying with the separation rules and thus ensuring secure key management. Besides instructions dedicated to secure key management, some additional instructions are dedicated to easy realization of block cipher modes and cryptographic protocols in general. In the next part of the manuscript, we show that the proposed separation principles can be extended also to a processor-coprocessor architecture. We propose a secure crypto-coprocessor, which can be used in conjunction with any general-purpose processor. To demonstrate its flexibility, the crypto-coprocessor is interconnected with the NIOS II, MicroBlaze and Cortex M1 soft-core processors. In the following part of the work, we examine the resistance of the HCrypt cryptoprocessor to differential power analysis (DPA) attacks. Following this analysis, we modify the architecture of the HCrypt processor in order to simplify its protection against side channel attacks (SCA) and fault injection attacks (FIA). We show that by rearranging blocks of the HCrypt processor at macroarchitecture level, the new HCrypt2 processor becomes natively more robust to DPA and FIA. Next, we study possibilities of dynamically reconfiguring selected parts of the processor - crypto-coprocessor architecture. The dynamic reconfiguration feature can be very useful when the cipher algorithm or its implementation must be changed in response to appearance of some vulnerability. Finally, the last part of the manuscript is dedicated to thorough testing and optimizations of both versions of the HCrypt crypto-processor. Architectures of crypto-processors and crypto-coprocessors are often vulnerable to software attacks targeting the disclosure of encryption keys. The thesis introduces separation rules enabling crypto-processor/coprocessors to support secure key management. Separation rules are implemented on novel HCrypt crypto-processor resistant to software attacks targetting the disclosure of encryption keys

Secure information exchanges over cyberspace is on the increase due to the convergence of wireless and mobile access technologies in all businesses. Accordingly, with the proliferation of diverse multicast group service subscriptions that are possible to co-exist within a single broadband network, there is also huge demand by the mobile subscribers to ubiquitously access these services over high speed broadband using their portable devices. Likewise, the Network Providers (NPs) invest hugely in infrastructure deployment to disseminate these services efficiently and concomitantly. Therefore, cyber security in any business is obligatory to restrict access of disseminated services to only authorised personnel. This becomes a vital requirement for a successful commercialisation of exchanged group services. The standard way to achieve cyber security in a wireless mobile multicast communication environment is through confidentiality using Group Key Management (GKM).The existing GKM schemes for secure wireless multicast from literature only target single group service confidentiality; however, the adoption of multiple group service confidentiality in them involve inefficient management of keys that induce huge performance overheads unbearable for real time computing. Therefore, a novel authenticated GKM scheme for multiple multicast group subscriptions known as slot based multiple group key management (SMGKM) is proposed. In the SMGKM, the handovers move across diverse decentralised clusters of homogeneous or heterogeneous wireless access network technologies while participating in multiple group service subscriptions. Unlike the conventional art, the SMGKM advances its security by integrating location based authentication and GKM functions. Both functions are securely offloaded from the Domain Key Distributor (DKD) to the intermediate cluster controllers, Area Key Distributors (AKDs), in a distributed fashion, using the proposed location based authenticated membership list (SKDL). A significant upgrade of fast handoff performance with reduced performance overheads of the SMGKM scheme is achieved. The developed numerical analysis and the simulation results display significant resource economy in terms of reduced rekeying transmission, communication bandwidth and storage overheads while providing enhanced security. The performance of the SMGKM in a high speed environment is also evaluated and has demonstrated that SMGKM outperforms the previous work. Finally, the SMGKM correctness against various attacks is verified using BAN logic, the eminent tool for analysing the widely deployed security protocols. The security analysis demonstrates that SMGKM can counteract the security flaws and redundancies identified in the chosen related art.

No description available.

Many mobile applications in wireless networks such as military battlefield, emergency response, and mobile commerce are based on the notion of secure group communications. Unlike traditional security protocols which concern security properties only, in this dissertation research we design and analyze a class of QoS-aware protocols for secure group communications in wireless networks with the goal to satisfy not only security requirements in terms of secrecy, confidentiality, authentication, availability and data integrity, but also performance requirements in terms of latency, network traffic, response time, scalability and reconfigurability. We consider two elements in the dissertation research: design and analysis. The dissertation research has three major contributions. First, we develop three "threshold-based" periodic batch rekeying protocols to reduce the network communication cost caused by rekeying operations to deal with outsider attacks. Instead of individual rekeying, i.e., performing a rekeying operation right after each group membership change event, these protocols perform batch rekeying periodically. We demonstrate that an optimal rekey interval exists that would satisfy an imposed security requirement while minimizing the network communication cost. Second, we propose and analyze QoS-aware intrusion detection protocols for secure group communications in mobile ad hoc networks to deal with insider attacks. We consider a class of intrusion detection protocols including host-based and voting-based protocols for detecting and evicting compromised nodes and examine their effect on the mean time to security failure metric versus the response time metric. Our analysis reveals that there exists an optimal intrusion detection interval under which the system lifetime metric can be best traded off for the response time performance metric, or vice versa. Furthermore, the intrusion detection interval can be dynamically adjusted based on the attacker behaviors to maximize the system lifetime while satisfying a system-imposed response time or network traffic requirement. Third, we propose and analyze a scalable and efficient region-based group key management protocol for managing mobile groups in mobile ad hoc networks. We take a region-based approach by which group members are broken into region-based subgroups, and leaders in subgroups securely communicate with each other to agree on a group key in response to membership change and member mobility events. We identify the optimal regional area size that minimizes the network communication cost while satisfying the application security requirements, allowing mobile groups to react to network partition/merge events for dynamic reconfigurability and survivability. We further investigate the effect of integrating QoS-aware intrusion detection with region-based group key management and identify combined optimal settings in terms of the optimal regional size and the optimal intrusion detection interval under which the security and performance properties of the system can be best optimized. We evaluate the merits of our proposed QoS-aware security protocols for mobile group communications through model-based mathematical analyses with extensive simulation validation. We perform thorough comparative analyses against baseline secure group communication protocols which do not consider security versus performance tradeoffs, including those based on individual rekeying, no intrusion detection, and/or no-region designs. The results obtained show that our proposed QoS-aware security protocols outperform these baseline algorithms. â / Ph. D.