The security of almost all public-key cryptography is based on some computationally hard problem. Most prominent are the problems of factoring integers into primes and computing discrete logarithms in finite groups. However, in the last two decades, several new public-key schemes have emerged that base their security on completely different problems. One such promising proposal is to base the security of public-key cryptography schemes on the difficulty of solving large systems of multivariate quadratic polynomial equations. A major challenge in designing these public-key systems is to embed an efficient trapdoor into the set of equations. Recently, a novel approach towards this problem was suggested by Gligoroski et al. cite{Gligoroski:2008:MQT}, using the concept of quasigroup string transformations. In this thesis we describe a methodology for identifying strong and weak keys in the newly introduced multivariate public-key signature scheme MQQ-SIG, which is based on this idea. We have conducted a large number of experiments based on Gröbner basis attacks, in order to classify the various parameters that determine the keys in MQQ-SIG. Our findings show that there are big differences in the importance of these parameters. The methodology consists of a classification of different parameters in the scheme, together with an introduction of concrete criteria on which keys to avoid and which to use. Additionally, we identified an unnecessary requirement in the original specification that required the quasigroups to fulfill a certain condition. Removing this restriction can potentially speed up the key generation process by a large factor. Having all this, we propose a new enhanced key generation algorithm for MQQ-SIG that will generate stronger keys and be more efficient than the original key generation method.

Traffic anomaly detection in backbone networks has received increased at-tention from the research community over the last years. A variety of tech-niques and implementations has been proposed in this area, some which hasbecome commercial products. However, studies have revealed that theseproducts are hardly used, mainly because of high false-positive rates andthe fact that manual inspection of alarms is a time consuming task for thenetwork administrator.Senatus is a recently proposed technique for combined anomaly detectionand root-cause analysis, originally proposed by Atef Abdelkefi. In this the-sis, we provide a complete high-performance implementation of Senatus,including a web Dashboard with overview of anomalies and the possibil-ity for manual fine-tuning of parameters. Furthermore, we have verifiedSenatus performance by comparing Senatus with a implementation of awell-known histogram-based anomaly detection technique.Our results show that Senatus performs very well for detection scans, andthat it matches the histogram-based anomaly detector for Denial of Service-attacks.

The video and computer gaming industry has seen a significant rise in popularity over the last decades and is now the worlds biggest digital entertainment industry [market-gamingvsmovies]. Where games meant Space Invaders and Doom in the old days, gaming is now everything from ultra-realistic shooter games to farm management simulators integrated in the Facebook platform, to games on our smartphones and tablets. This popularity has brought with it the attention of hackers and exploiters, and game cheats flourish in the shady parts of the internet. This thesis has two parts. The first part presents a background study, an oveorview of today's situation in regard to cheating and anti-cheating in online games. The second part is a case study about bots and bot detection in Browser-Based Multiplayer Games (BBMG).In the background study, the main finding is that there are over twenty websites selling cheats or cheat subscriptions, and that the type of cheats available for a game is heavily dependent on the game genre. Most or all first-person shooters (FPS) have available aimbots and wallhacks, and all major massively multiplayer online games (MMO) are exposed to bot programs. The cheats are being sold either alone or through monthly subscriptions, allowing free use of all cheats for all supported games by that vendor. There have been many anti-cheat actors over the past decade, but three known services being continually developed. The two biggest are Valve Anti-Cheat, used by most games managed through Valve's online gaming platform Steam, and PunkBuster, which protects amongst others the Battlefield series. The last big anti-cheat software is the proprietary Warden, used only in Blizzard's own games like the Diablo. Warcraft and Starcraft games. Many cheats are still able to bypass the security mechanisms provided by these, and it is a continuos arms race between cheat developers and anti-cheat developers, just like in the virus and anti-virus industry.In the case study, two bots were written for a non-disclosed BBMG and their performance was tested quantitatively by playing several game accounts in parallel. It showed that bot use yields large performance gains both in the early game stages and for advanced players. As a result of the case study research on bots in online games, a Bot-Detection System (BDS) is created and presented in the last chapter. The goal of the BDS is to detect the use of bots in BBMG by identifying a set of attributes and comparing these to average human behavior. A score system ranging from 0 to 100 is introduced, where the average human behavior is defined as 0, while increasing non-human behavior is given a score >0, with max 100. The BDS is then employed on the two bots and returns scores of 64 and 52, while the six human play testers receive scores of 1 or 0.

Etter krav fra Norges vassdrags- og energidirektorat (NVE) er alle norske nettselskaper innen kraftbransjen pålagt å installere Avanserte Måle- og Styringssystemer (AMS) for alle sine målepunkter innen 1.januar 2017. AMS er en integrering av IKT i kraftforsyningen som muliggjør toveis kommunikasjon for å effektivisere avregning, bytte av kraftleverandør samt danne fundament for det framtidige dynamisk smart strømnett.I et hvert distribuert kommunikasjonssystem må informasjonssikkerheten håndteres etter vurdert risiko et slikt system innfører. Etter vurderinger av NVEs funksjonskrav ble følgende områder for informasjonssikkerhet i AMS definert; sikring av fysisk utstyr, sikkerhet i hardware, sikkerhet i software, sikring av kommunikasjonsteknologi, organisatorisk informasjonssikkerhet. Fundamentalt for distribuerte systemer er sikker datakommunikasjon og det eksisterer mange typer angrep mot AMS om kommunikasjonsnettverket ikke er tilstrekkelig sikret. Vurderingene av konsekvenser ved suksessfulle angrep viser at avhengighet mellom funksjoner, spesielt styringssignaler og konfigurasjonskommandoer, generelt fører til økt kompleksitet og gir større konsekvenser enn angrep mot målerverdier. Ved enkelte tilfeller av suksessfulle angrep mot styringssignaler i AMS-nettverket, vurderes konsekvensene til å være samfunnmessige da det kan resultere i kaskadeeffekter og ustabilitet for hele kraftnettet.I denne oppgaven blir det presentert en sikkerhetsarkitektur for kommunikasjon mellom sluttbruker og nettselskap som kan tilstrekkelig nivå av sikkerhet relativt til konsekvensene av angrep. Arkitekturen er basert på forsvar i dybden og implementerer to lag med sikre ende-til-ende forbindelser basert på DLMS/COSEM og IP/IPsec.

This paper looks at two MAC protocols for wireless sensor networksfor use in industrial applications developed at the Ubicom Lab, at theUniversity of Ulsan. A theoretical comparison of the MAC protocolsare performed to understand more about the benefits and downsidesto both of them, and experimental scenarios to validate the theoreticalanalysis are suggested. Theoretical analysis suggests that BigMAC hasan advantage in environments with high interference and frequent linkbreaks, while I-MAC has an advantage when the network topology isstable.

Today, major IT-companies, such as Microsoft, Amazon and Google, are offering online storage services to their customers. This is a favourable solution -- as opposed to regular storage -- in terms of low costs, reliability, scalability and capacity. However, important security features such as data privacy and integrity are often absent.To address these issues, a cryptographic architecture is proposed that ensures the confidentiality and integrity of the data stored by users, independent of the trust of the provider. This includes secure sharing of private data among users of the same service.The underlying cryptographic architecture is based on existing open source systems and cryptographic primitives. The architecture was implemented as a reusable general library in Java. An Android client was created, and several performance tests were conducted. The proof of concept system shows that it is possible to implement the proposed scheme, and that the cryptographic operations does not significantly affect the user experience on an Android device. Possible weaknesses of the scheme are identified.We present a scheme for secure storage and sharing of files on an untrusted server, and argue for its validity. To support streaming functionality, the scheme could be extended with hash trees to validate small parts of a file at the time.

Performance analysis and comparison of different techniques used for anomaly detection in packet switched backbone networks.

Password based logon schemes have many security weaknesses. For secure environments smart card and biometric based authentication solutions are available as replacement for standard password based systems. Nevertheless, the cost of deployment and maintenance of these systems is quite high. On the other hand, mobile network operators have a huge base of deployed smart cards that can be reused to provide authentication in other spheres significantly reducing costs. In this project we present a study of how mobile phones can be used to provide a secure low-cost two-factor workstation logon solution.To find and study the available mobile phone based authentication architectures and come up with workstation logon architecture the study of relevant technologies utilized in these solutions: UMTS networks, Bluetooth communication, Remote Authentication Dial in User Service (RADIUS), authentication and authorization in Windows, Linux, and MAC OS X. The analysis of available mobile phone based authentication schemes like SIM Strong schemes based on EAP-SIM, Session-ID based schemes, and OTP based schemes are also added.A solution for Linux workstation logon process has been proposed in the thesis using the Pluggable Authentication Module (PAM). The Solution uses 2 factors for authentication, one is the static password and the second factor is the mobile based authentication using a 13 character long OTP. With adding the existing technology and giving the administrator the option of selecting the authentication method for user makes the solution more suitable for an enterprise.

The pervasive computing environment for heterogeneous network is on a continuous rise. The ability to interact and control network devices with different functionalities within office and home environment could be very beneficial to a lot of users. The service discovery in computers and mobile devices enabled them to interact with one another through wireless and heterogeneous wired networks. Services advertise their existence in a dynamic way and devices are designed with this capability to discover these services and its properties automatically. These devices are though based on different technologies but are still able to communicate and discover one another based on existing service discovery architectures. It is notable that a significant number of networked devices are now mobile and these mobile devices make service discovery more challenging.In future mobile multi-domain multi-language environments, a service can be anything and introduced by anybody. Consequently, same or equivalent services may have different names and services with same name or type may be completely different. Existing service discovery systems are incapable of handling these situations. We have implemented a service discovery system which supports semantics to service descriptions. It allows any user to act as a service provider and introduce any service at any time. The service provider can define any service as equivalent to any existing service and in any language as wanted. In addition, it is capable to find services that are not exact matches of the requested ones. More semantics are introduced through attributes like EquivalenceClass, ParentType and Keywords. The test conducted on this system in real time proves that the system is efficient and can be applied in real life.

This thesis presents the combination of MPLS-TP protocol with an integrated hybridnetwork, the Opmigua network. It is presented that the MPLS-TP protocol is applicableand follows all the requirements to be compatible with an Opmigua network. Differentnetwork scenarios, combining packet and circuit switching properties with MPLS-TPlabels, are presented. At the beginning of this thesis, are provided the characteristics and requirements of MPLS-TP protocol which the standardization of this is on going. Furthermore, it is explained how the MPLS-TP management and the forwarding plane work. Some references are also given not only to OAM mechanisms, but also to control plane that the MPLS-TP uses. We use both, global and local significance MPLS-TP labels for distinguishing theGuaranteed Service Traffic (GST) packets from Statistical Multiplexing (SM) packets.Using this method, we have concluded some results, as it concerns GST and SMtraffic. GST packets take a global significance label value until to reach the destination node. On the other hand, SM packets take local significance labels for each path into an Opmigua network which follow Optical Packet Switch (OPS) networks. We have proposed a new method for differentiation of packets from low to high priority using extension headers of Internet Protocol v6 either Destination Options Header(DOH) or MPLS-TP as an extension header. The result that we have derived is highand low priority packets are differentiated at ingress Opmigua network which GST packets take global significance MPLS-TP label following Optical Cross Connect (OXC) network and SM packets change per each Label Switched Path (LSP) local significance MPLS-TP labels until to reach the destination. Finally, two MPLS-TP path protection schemes, facility bypass and restoration usingdetours were combined with Opmigua network to provide failures for both, GuaranteedService Traffic (GST) packets and Statistical Multiplexing (SM) packets.