Context. A huge majority of the current Internet traffic is information dissemination. Information-Centric Networking (ICN) is a future networking paradigm that focuses on global level information dissemination. In ICN, the communication is defined in terms of requesting and providing Named Data Objects (NDO). NetInf is a future networking architecture based on Information-Centric Networking principles. Objectives. In this thesis, a global routing solution for ICN has been implemented. The authority part of NDO's name is mapped to a set of routing hints each with a priority value. Multiple NDOs can share the same authority part and thus the first level aggregation is provided. The routing hints are used to forward a request for a NDO towards a suitable copy of the NDO. The second level aggregation is achieved by aggregating high priority routing hints on low priority routing hints. The performance and scalability of the routing implementation are evaluated with respect to global ICN requirements. Furthermore, some of the notable challenges in implementing global ICN routing are identified. Methods. The NetInf global routing solution is implemented by extending NEC's NetInf Router Platform (NNRP). A NetInf testbed is built over the Internet using the extended NNRP implementation. Performance measurements have been taken from the NetInf testbed. The performance measurements have been discussed in detail in terms of routing scalability. Results. The performance measurements show that hop-by-hop transport has significant impact on the overall request forwarding. A notable amount of time is taken for extracting and inserting binary objects such as routing hints at each router. Conclusions. A more suitable hop-by-hop transport mechanism can be evaluated and used with respect to global ICN requirements. The NetInf message structure can be redefined so that binary objects such as routing hints can be transmitted more efficiently. Apart from that, the performance of the global routing implementation appears to be reasonable. As the NetInf global routing solution provides two levels of aggregation, it can be scalable as well.

An extensive analysis of attribute-based encryption (ABE) in systems with resource constrained devices is performed. Two system solutions of how ABE can be performed in such systems are proposed, one where the ABE operations are performed at the resource constrained devices and one where ABE is performed at a powerful server. The system solutions are discussed with three different ABE schemes. Two of the schemes are the traditional key policy ABE (KP-ABE) and ciphertext policy ABE (CP-ABE). The third scheme is using KP-ABE to simulate CP-ABE, in an attempt to benefit from KP-ABE being computationally cheaper than CP-ABE while maintaining the intuitive way of using CP-ABE. ABE is a computationally expensive encryption method which might not be feasible to perform at the resource constrained sensors, depending on the hardware. An implementation of a CP-ABE scheme with a 128 bit security level was written and used to evaluate the feasibility of ABE on a sensor equipped with an ARM Cortex-M3 processor having 32 kB RAM and 256 kB flash. It is possible to perform CP-ABE on the sensor used in this project. The limiting factor of feasibility of ABE on the sensor is the RAM size. In this case policy sizes up to 12 attributes can be performed on the sensor. The results give an idea of the feasibility of encryption with ABE on sensors. In addition to the results several ways of improving performance of ABE on the sensor are discussed.

The Named Data Networking (NDN) is a new Internet architecture that changes the network semantic from packet delivery to content retrieval and promises benefits in areas such as content distribution, security, mobility support, and application development. While the basic NDN architecture applies to any network environment, local area networks (LANs) are of particular interest because of their prevalence on the Internet and the relatively low barrier to deployment. In this dissertation, I design NDN protocols and implement NDN software, to make NDN communication in LAN robust and efficient. My contributions include: (a) a forwarding behavior specification required on every NDN node; (b) a secure and efficient self-learning strategy for switched Ethernet, which discovers available contents via occasional flooding, so that the network can operate without manual configuration, and does not require a routing protocol or a centralized controller; (c) NDN-NIC, a network interface card that performs name-based packet filtering, to reduce CPU overhead and power consumption of the main system during broadcast communication on shared media; (d) the NDN Link Protocol (NDNLP), which allows the forwarding plane to add hop-by-hop headers, and provides a fragmentation-reassembly feature so that large NDN packets can be sent directly over Ethernet with limited MTU.

No description available.

Severe weather impacts life and in this dire condition, people rely on communication, to organize relief and stay in touch with their loved ones. In such situations, cellular network infrastructure\footnote{We refer to cellular network infrastructure as infrastructure for the entirety of this document} might be affected due to power outage, link failures, etc. This urges us to look at Ad-hoc mode of communication, to offload major traffic partially or fully from the infrastructure, depending on the status of it. We look into threefold approach, ranging from the case where the infrastructure is completely unavailable, to where it has been replaced by make shift low capacity mobile cellular base station. First, we look into communication without infrastructure and timely, dissemination of weather alerts specific to geographical areas. We look into the specific case of floods as they affect significant number of people. Due to the nature of the problem we can utilize the properties of Information Centric Networking (ICN) in this context, namely: i) Flexibility and high failure resistance: Any node in the network that has the information can satisfy the query ii) Robust: Only sensor and car need to communicate iii) Fine grained geo-location specific information dissemination. We analyze how message forwarding using ICN on top of Ad hoc network, approach compares to the one based on infrastructure, that is less resilient in the case of disaster. In addition, we compare the performance of different message forwarding strategies in VANETs (Vehicular Adhoc Networks) using ICN. Our results show that ICN strategy outperforms the infrastructure-based approach as it is 100 times faster for 63\% of total messages delivered. Then we look into the case where we have the cellular network infrastructure, but it is being pressured due to rapid increase in volume of network traffic (as seen during a major event) or it has been replaced by low capacity mobile tower. In this case we look at offloading as much traffic as possible from the infrastructure to device-to-device communication. However, the host-oriented model of the TCP/IP-based Internet poses challenges to this communication pattern. A scheme that uses an ICN model to fetch content from nearby peers, increases the resiliency of the network in cases of outages and disasters. We collected content popularity statistics from social media to create a content request pattern and evaluate our approach through the simulation of realistic urban scenarios. Additionally, we analyze the scenario of large crowds in sports venues. Our simulation results show that we can offload traffic from the backhaul network by up to 51.7\%, suggesting an advantageous path to support the surge in traffic while keeping complexity and cost for the network operator at manageable levels. Finally, we look at adaptive bit-rate streaming (ABR) streaming, which has contributed significantly to the reduction of video playout stalling, mainly in highly variable bandwidth conditions. ABR clients continue to suffer from the variation of bit rate qualities over the duration of a streaming session. Similar to stalling, these variations in bit rate quality have a negative impact on the users’ Quality of Experience (QoE). We use a trace from a large-scale CDN to show that such quality changes occur in a significant amount of streaming sessions and investigate an ABR video segment retransmission approach to reduce the number of such quality changes. As the new HTTP/2 standard is becoming increasingly popular, we also see an increase in the usage of HTTP/2 as an alternative protocol for the transmission of web traffic including video streaming. Using various network conditions, we conduct a systematic comparison of existing transport layer approaches for HTTP/2 that is best suited for ABR segment retransmissions. Since it is well known that both protocols provide a series of improvements over HTTP/1.1, we perform experiments both in controlled environments and over transcontinental links in the Internet and find that these benefits also “trickle up” into the application layer when it comes to ABR video streaming where HTTP/2 retransmissions can significantly improve the average quality bitrate while simultaneously minimizing bit rate variations over the duration of a streaming session. Taking inspiration from the first two approaches, we take into account the resiliency of a multi-path approach and further look at a multi-path and multi-stream approach to ABR streaming and demonstrate that losses on one path have very little impact on the other from the same multi-path connection and this increases throughput and resiliency of communication.

京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第19131号 / 情博第577号 / 新制||情||101(附属図書館) / 32082 / 京都大学大学院情報学研究科通信情報システム専攻 / (主査)教授 高橋 達郎, 教授 守倉 正博, 高橋 豊 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DGAM

The underlying architecture of the Internet has been mostly the same since its beginning in the 1960s and the TCP/IP protocol stack remains ubiquitous. However the Internet is today used for much wider purposes than what was originally intended and now the most common use of the Internet is for the distribution of various forms of content. Information Centric Networking (ICN) is an alternative architecture responding to this change in usage, intended to be more prepared to handle the new requirements of the Internet not only today but also in the future. The primary concern in ICN is the secure and efficient distribution of content. Current ICN research often concerns applications on various disaster scenarios as it is believed that ICN has properties that match the requirements of such scenarios. In this thesis that research is continued by developing an especially designed information retention solution, using the existing ICN implementation of Content Centric Networking (CCN). The aim is to maximisise and prolong the availability of as much content as possible in disaster-stricken networks by preemptively replicating content across the network topology. The solution is then evaluated against a scenario set in a network topology consisting of virtual machines. The final result is that the solution performs satisfactorily and thus demonstrate the potential of ICN when applied to such scenarios. / Internets underliggande arkitektur har varit i stort sett oförändrad sedan sin begynnelse på 1960-talet, och TCP/IP protokollstacken är fortsatt universell. Dock så används Internet idag för betydligt bredare ändamål än de ursprungliga syftena, och nu används Internet främst för att distribuera olika former av innehåll. Information Centric Networking (ICN) är en alternativ arkitektur som svarar på denna förändring i använding, avsedd att vara mer förberedd att hantera de nya kraven på Internet inte bara idag men också i framtiden. Den största angelägenheten i ICN är att distribuera innehåll på ett säkert och effektivt vis. Nuvarande forskning inom ICN handlar ofta om tillämpningar på olika sorters katastrofscenarier då tron är att ICN har egenskaper som motsvarar kraven hos sådana scenarier. I den här uppsatsen fortsätts denna forskning genom att en speciellt formgiven informationsbevaringslösning utvecklas, som nyttjar den existerande ICN-implementationen Content Centric Networking (CCN). Målet är att maximera och förlänga tillgängligheten av så mycket innehåll som möjligt i katastrofdrabbade nätverk genom att i förebyggande syfte replikera innehåll genom nätverkstopologin. Lösningen evalueras sedan mot ett scenario som utspelas i en nätverkstopologi utav virtuella maskiner. Det slutgiltiga resultatet är att lösningen presterar tillfredsställande och på så vis demonstrerar potentialen hos ICN vid tillämpning på sådana scenarion.

Um dos principais desafios em Redes Centradas em Informação (ICN) é como prover controle de acesso à publicação e recuperação de conteúdos. Apesar das potencialidades, as soluções existentes, geralmente, consideram um único usuário agindo como publicador. Ao lidar com múltiplos publicadores, elas podem levar a uma explosão combinatória de chaves criptográficas. As soluções projetadas visando a múltiplos publicadores, por sua vez, dependem de arquiteturas de redes específicas e/ou de mudanças nessas para operar. Nesta dissertação é proposta uma solução, apoiada em criptografia baseada em atributos, para controle de acesso a conteúdos. Nessa solução, o modelo de segurança é voltado a grupos de compartilhamento seguro, nos quais todos os usuários membros podem publicar e consumir conteúdos. Diferente de trabalhos anteriores, a solução proposta mantém o número de chaves proporcional ao de membros nos grupos e pode ser empregada em qualquer arquitetura ICN de forma gradual. A proposta é avaliada quanto ao custo de operação, à quantidade de chaves necessárias e à eficiência na disseminação de conteúdos. Em comparação às soluções existentes, ela oferece maior flexibilidade no controle de acesso, sem aumentar a complexidade do gerenciamento de chaves e sem causar sobrecustos significativos à rede. / One of the main challenges in Information-Centric Networking (ICN) is providing access control to content publication and retrieval. In spite of the potentialities, existing solutions often consider a single user acting as publisher. When dealing with multiple publishers, they may lead to a combinatorial explosion of cryptographic keys. Those solutions that focus on multiple publishers, on the other hand, rely on specific network architectures and/or changes to operate. In this dissertation, it is proposed a solution, supported by attribute-based encryption, for content access control. In this solution, the security model is focused on secure content distribution groups, in which any member user can publish to and retrieve from. Unlike previous work, the proposed solution keeps the number of cryptographic keys proportional to the number of group members, and may even be adopted gradually in any ICN architecture. The proposed solution is evaluated with respect to the overhead it imposes, number of required keys, and efficiency in the content dissemination. In contrast to existing solutions, it offers higher access control flexibility, without increasing key management process complexity and without causing significant network overhead.

Um dos principais desafios em Redes Centradas em Informação (ICN) é como prover controle de acesso à publicação e recuperação de conteúdos. Apesar das potencialidades, as soluções existentes, geralmente, consideram um único usuário agindo como publicador. Ao lidar com múltiplos publicadores, elas podem levar a uma explosão combinatória de chaves criptográficas. As soluções projetadas visando a múltiplos publicadores, por sua vez, dependem de arquiteturas de redes específicas e/ou de mudanças nessas para operar. Nesta dissertação é proposta uma solução, apoiada em criptografia baseada em atributos, para controle de acesso a conteúdos. Nessa solução, o modelo de segurança é voltado a grupos de compartilhamento seguro, nos quais todos os usuários membros podem publicar e consumir conteúdos. Diferente de trabalhos anteriores, a solução proposta mantém o número de chaves proporcional ao de membros nos grupos e pode ser empregada em qualquer arquitetura ICN de forma gradual. A proposta é avaliada quanto ao custo de operação, à quantidade de chaves necessárias e à eficiência na disseminação de conteúdos. Em comparação às soluções existentes, ela oferece maior flexibilidade no controle de acesso, sem aumentar a complexidade do gerenciamento de chaves e sem causar sobrecustos significativos à rede. / One of the main challenges in Information-Centric Networking (ICN) is providing access control to content publication and retrieval. In spite of the potentialities, existing solutions often consider a single user acting as publisher. When dealing with multiple publishers, they may lead to a combinatorial explosion of cryptographic keys. Those solutions that focus on multiple publishers, on the other hand, rely on specific network architectures and/or changes to operate. In this dissertation, it is proposed a solution, supported by attribute-based encryption, for content access control. In this solution, the security model is focused on secure content distribution groups, in which any member user can publish to and retrieve from. Unlike previous work, the proposed solution keeps the number of cryptographic keys proportional to the number of group members, and may even be adopted gradually in any ICN architecture. The proposed solution is evaluated with respect to the overhead it imposes, number of required keys, and efficiency in the content dissemination. In contrast to existing solutions, it offers higher access control flexibility, without increasing key management process complexity and without causing significant network overhead.

Um dos principais desafios em Redes Centradas em Informação (ICN) é como prover controle de acesso à publicação e recuperação de conteúdos. Apesar das potencialidades, as soluções existentes, geralmente, consideram um único usuário agindo como publicador. Ao lidar com múltiplos publicadores, elas podem levar a uma explosão combinatória de chaves criptográficas. As soluções projetadas visando a múltiplos publicadores, por sua vez, dependem de arquiteturas de redes específicas e/ou de mudanças nessas para operar. Nesta dissertação é proposta uma solução, apoiada em criptografia baseada em atributos, para controle de acesso a conteúdos. Nessa solução, o modelo de segurança é voltado a grupos de compartilhamento seguro, nos quais todos os usuários membros podem publicar e consumir conteúdos. Diferente de trabalhos anteriores, a solução proposta mantém o número de chaves proporcional ao de membros nos grupos e pode ser empregada em qualquer arquitetura ICN de forma gradual. A proposta é avaliada quanto ao custo de operação, à quantidade de chaves necessárias e à eficiência na disseminação de conteúdos. Em comparação às soluções existentes, ela oferece maior flexibilidade no controle de acesso, sem aumentar a complexidade do gerenciamento de chaves e sem causar sobrecustos significativos à rede. / One of the main challenges in Information-Centric Networking (ICN) is providing access control to content publication and retrieval. In spite of the potentialities, existing solutions often consider a single user acting as publisher. When dealing with multiple publishers, they may lead to a combinatorial explosion of cryptographic keys. Those solutions that focus on multiple publishers, on the other hand, rely on specific network architectures and/or changes to operate. In this dissertation, it is proposed a solution, supported by attribute-based encryption, for content access control. In this solution, the security model is focused on secure content distribution groups, in which any member user can publish to and retrieve from. Unlike previous work, the proposed solution keeps the number of cryptographic keys proportional to the number of group members, and may even be adopted gradually in any ICN architecture. The proposed solution is evaluated with respect to the overhead it imposes, number of required keys, and efficiency in the content dissemination. In contrast to existing solutions, it offers higher access control flexibility, without increasing key management process complexity and without causing significant network overhead.