The paper deals with geographical speed of IP data transmission in the European Internet. We measure the speed using a set of PlanetLab servers with known physical location. Based on the results we identify typical maximum geographical distance that data can travel for given communication latency, provided that the linear latency-to-distance transformation is preferred. An estimation of the typical maximum distance between two Internet nodes may help to improve certain geolocation problems. We show that the typical maximum distance results in a smaller delimited area of possible node locations, still including the correct location. DOI: http://dx.doi.org/10.5755/j01.itc.46.4.16113

Quantum key distribution (QKD) relies on the laws of physics to establish a symmetric binary key between remote parties. A QKD link involves the realization of a quantum channel for the transmission of quantum key material encoded in certain photon properties, as well as a public channel for verification of the exchanged key material. This paper deals with the mutual dependence of these channels and analyzes the impact of performance of both channels on the overall key material establishment process. This paper presents measurement data obtained under laboratory conditions as well as the results obtained by establishing a virtual QKD link. Despite the common beliefs that increased quantum bit error rate implies a larger amount of traffic on the public channel, our measurements prove the opposite. The obtained data clearly show that the public channel has a major impact on the overall performance of the QKD link.

Device-independent Internet spatial location is needed for many purposes, such as data personalisation and social behaviour analysis. Internet spatial databases provide such locations based the IP address of a device. The free to use databases are natively included into many UNIX and Linux operating systems. These systems are predominantly used for e-shops, social networks, and cloud data storage. Using a constructed ground truth dataset, we comprehensively evaluate these databases for null responses, returned country/region/city, and distance error. The created ground truth dataset differs from others by covering cities with both low and high populations and maintaining only devices that follow the rule of one IP address per ISP (Internet Service Provider) and per city. We define two new performance metrics that show the effect of city population and trustworthiness of the results. We also evaluate the databases against an alternative measurement-based approach. We study the reasons behind the results. The data evaluated comes from Europe. The results may be of use for engineers, developers and researchers that use the knowledge of geographical location for related data processing and analysis, such as marketing.

Quantum Key Distribution (QKD), based on the laws of physics rather than the computational complexity of mathematical problems, provides a secure way of establishing symmetrical binary keys between two geographically distant users. The keys are secure from eavesdropping during transmission and QKD ensures that any third party’s knowledge of the key is reduced to a minimum. In recent years, a noticeable progress in the development of quantum equipment has been reflected through a number of successful demonstrations of QKD technology. While they show the great achievements of QKD, many practical difficulties still need to be resolved, such as to provide better service differentiation. These networks are characterized as being multihop in nature where the consumption key rate is often higher than the charging key rate, which means that the links are available for a limited period of time only. Such features impose several challenges on the effective modeling and evaluation of reliability as well as finding appropriate Quality of Service (QoS) solution. This thesis focuses on research in the field of QKD for securing real-time communication by supporting QoS in QKD networks including a novel QoS model and novel distributed reactive routing protocol to achieve high-level scalability and minimize the consumption of key material used for securing routing data. As research in QKD networks grows larger and more complex, the need for highly accurate and scalable simulation technologies becomes important to assess the practical feasibility and foresee difficulties in the practical implementation of theoretical achievements. Due to the specificity of QKD link which requires optical/quantum and Internet connection between the network nodes, it is very costly to deploy a complete testbed containing multiple network hosts and links to validate and verify a certain network algorithm or protocol. The network simulators in these circumstances save a lot of money and time in accomplishing such task. A simulation environment offers the creation of complex network topologies, a high degree of control and repeatable experiments, which in turn allows researchers to conduct exactly the same experiments and confirm their results. This thesis describes the design and implementation of QKD network simulation module which was developed in the network simulator of version 3 (NS-3). The module supports simulation of QKD network in overlay mode or in a single TCP/IP mode. Therefore, it can be used for simulation of other network technologies regardless of QKD. Implemented simulation model was used for verification of proposed QoS solution. A number of simulations were performed. The obtained data have confirmed the primary thesis of this study, that it is possible to use real-time applications in QKD networks.

As research in quantum key distribution network technologies grows larger and more complex, the need for highly accurate and scalable simulation technologies becomes important to assess the practical feasibility and foresee difficulties in the practical implementation of theoretical achievements. In this paper, we described the design of simplified simulation environment of the quantum key distribution network with multiple links and nodes. In such simulation environment, we analyzed several routing protocols in terms of the number of sent routing packets, goodput and Packet Delivery Ratio of data traffic flow using NS-3 simulator.

Quantum Key Distribution (QKD), based on the laws of physics rather than the computational complexity of mathematical problems, provides an information-theoretically secure way of establishing symmetrical binary keys between two geographically distant users. This paper is oriented to the practical realization of QKD public channels which are usually implemented as overlay point-to-point connections. We address the problem of minimizing the key material consumption by changing packet overhead. Our results show that the efficiency of communication in overlay QKD networks may increase when packets of larger sizes are used. However, this tuning directly affects the performance of overall communication. We evaluated this approach using an overlay network module which was implemented in the NS-3 simulator. The obtained results can be used for other overlay networks as well.

A mobile ad hoc network is a collection of mobile nodes which communicate without a fixed backbone or centralized infrastructure. Due to the frequent mobility of nodes, routes connecting two distant nodes may change. Therefore, it is not possible to establish a priori fixed paths for message delivery through the network. Because of its importance, routing is the most studied problem in mobile ad hoc networks. In addition, if the Quality of Service (QoS) is demanded, one must guarantee the QoS not only over a single hop but over an entire wireless multi-hop path which may not be a trivial task. In turns, this requires the propagation of QoS information within the network. The key to the support of QoS reporting is QoS routing, which provides path QoS information at each source. To support QoS for real-time traffic one needs to know not only minimum delay on the path to the destination but also the bandwidth available on it. Therefore, throughput, end-to-end delay, and routing overhead are traditional performance metrics used to evaluate the performance of routing protocol. To obtain additional information about the link, most of quality-link metrics are based on calculation of the lost probabilities of links by broadcasting probe packets. In this paper, we address the problem of including multiple routing metrics in existing routing packets that are broadcasted through the network. We evaluate the efficiency of such approach with modified version of DSDV routing protocols in ns-3 simulator.

of unused packet fields and information encoding in traffic behaviour. The first element

of unused packet fields and information encoding in traffic behaviour. The first element

Quantum key distribution (QKD) is based on the laws of quantum physics and therefore it can guarantee the highest level of security. It is used to establish the key that is used for further symmetrical encryption. Since QKD consists of several phases in which the key is reduced, it is necessary to define the equation by which the length of the raw key is calculated. In this paper, we analyse all QKD phases with an emphasis on the explanation of the process of shortening the initial key. The results are verified with a large number of tests using a quantum cryptography simulator. DOI: http://dx.doi.org/10.5755/j01.eee.21.6.13768

Steganography is method of hiding data inside of existing channels of communications. SIP is one of the key protocols used to implement Voice over IP. It is used for establishing, managing and termination of the communication session. During the call, SIP is used for changing parameters of the session as well as for the transfer of DTMF or instant messages. We analyzed scenario where two users (Alice and Bob) want to exchange hidden message via SIP protocol. Their call is established over Kamailio, SIP Proxy server. We were interested in a number of SIP messages that are exchanged during the call with an average duration of 60 seconds. Then we used SNORT IDS with hard coded rules and AD.SNORT (Anomaly Detection) for detecting irregularities while we increased the number of SIP messages. Finally, we calculated the available steganographic bandwidth, amount of hidden data that can be transferred in these messages. The results obtained from the experiments show that it is possible to create a covert channel over SIP with bandwidth of several kbps.

Global System for Mobile communication (GSM) is the most widespread technology for mobile communications in the world and serving over 7 billion users. Since first publication of system documentation there has been notified a potential safety problem’s occurrence. Selected types of attacks, based on the analysis of the technical feasibility and the degree of risk of these weaknesses, were implemented and demonstrated in laboratory of the VSB-Technical University of Ostrava, Czech Republic. These vulnerabilities were analyzed and afterwards possible attacks were described. These attacks were implemented using open-source tools, software programmable radio USRP (Universal Software RadioPeripheral) and DVB-T (Digital Video Broadcasting – Terrestrial) receiver. GSM security architecture is being scrutinized since first public releases of its specification mainly pointing out weaknesses in authentication and ciphering mechanisms. This contribution also summarizes practically proofed and used scenarios that are performed using opensource software tools and variety of scripts mostly written in Python. Main goal of this paper is in analyzing security issues in GSM network and practical demonstration of selected attacks.

It is well known that Quantum Key Distribution (QKD) can be used with the highest level of security for distribution of the secret key, which is further used for symmetrical encryption. B92 is one of the oldest QKD protocols. It uses only two non-orthogonal states, each one coding for one bit-value. It is much faster and simpler when compared to its predecessors, but with the idealized maximum efficiencies of 25% over the quantum channel. B92 consists of several phases in which initial key is significantly reduced: secret key exchange, extraction of the raw key (sifting), error rate estimation, key reconciliation and privacy amplification. QKD communication is performed over two channels: the quantum channel and the classical public channel. In order to prevent a man-in-the-middle attack and modification of messages on the public channel, authentication of exchanged values must be performed. We used Wegman-Carter authentication because it describes an upper bound for needed symmetric authentication key. We explained the reduction of the initial key in each of QKD phases.