Seminar Series on Advances in Telecommunications, Networking and Computing

For this year's program, please, click here!

Program in 2009

Program in details

Wireless Security Gets Physical

Abstract: This talk is concerned with the impact of the physical layer and physical locations on the security of wireless networks and their applications. We discuss the problem of location verification, and then show how location awareness can enable some basic security primitives like broadcast authentication. We further look at the problem of anti-jamming broadcast communication and show how the limitations of the wireless channel introduce a key-establishment/anti-jamming dependency cycle; we then describe a solution that breaks this cycle.

Short bio: Srdjan Capkun received the Dipl.Ing. Degree in Electrical Engineering / Computer Science from University of Split, Croatia (1998), and the Ph.D. degree (Docteur es Sciences) in Communication Systems from EPFL (Swiss Federal Institute of Technology - Lausanne) (2004). He was a postdoctoral researcher in the Networked & Embedded Systems Laboratory (NESL), University of California Los Angeles and an Assistant Professor in the Informatics and Mathematical Modeling Department (IMM), Technical University of Denmark (DTU). Since September 2006, he is an Assistant Professor in the Department of Computer Science, ETH Zürich. His main interests are in the design and analysis of security protocols and systems for wireless and wireline networks.

Dynamic Data Management in Mobile Ad Hoc Networks<

Abstract: In ad hoc networks, due to frequent network partition, data accessibility is lower than that in conventional fixed networks. This problem can be solved by replicating data items on mobile hosts. However, the movement of nodes, limited storage space and frequent disconnections limit the availability. In this talk, I will discuss three dynamic replica allocation methods by taking into account the read/write patterns at mobile hosts for each data item, the status of the network connection, topology and by considering a periodic updates and integrating user profiles of mobile users' schedules. These methods allow dynamic relocation of replicas to maintain availability. I will discuss the performance evaluation of our proposed methods and show their comparison using extensive simulation experiments based on parameters such as write frequency, relocation period, data accessibility, radio communication range, limited memory, among others. In addition, I will provide an overview of different consistency conditions needed in this environment. This talk is based on two “IEEE Transaction on Mobile Computing” papers of the speaker.

Short bio: Sanjay Kumar Madria received his Ph.D. in Computer Science from Indian Institute of Technology, Delhi, India in 1995. He is an Associate Professor, Department of Computer Science at the University of Missouri-Rolla, USA. Earlier he was Visiting Assistant Professor in the Department of Computer Science, Purdue University, West Lafayette, USA. He has also held appointments at Nanyang Technological University in Singapore. He has published more than 120 Journal and conference papers in the areas of mobile and sensor data management. He has organized International conferences, workshops and presented tutorials in the areas of mobile computing. He has given keynotes, invited talks and served as panelists in National Science Foundation of USA, Canada, Hong Kong and Sweden. His research is supported by NSF, DOE, UMRB and industrial grants for over $1.6M. He was awarded JSPS fellowship in 2006 and Air Force Research Award in 2008. He is IEEE Senior Member, and IEEE and ACM Distinguished Speaker.

More information: http://web.mst.edu/~madrias/

Considerations on the Evolution of Programs Based on Chemical Computing

Abstract: A computation model inspired by chemistry is introduced, as a way to express highly parallel programs capable of self-replication and self-modification. The motivation for such an algorithmic chemistry is to enable programs to self-evolve and adapt to new situations automatically. This is a challenging task due to the dynamic code rewriting process, the stochastic execution order, and the inherently decentralized evolution process.

This talk gives an overview of algorithmic chemistries and their role as computation models, and then introduces the (mostly unsolved) problem of evolving programs running in such chemistries. We share some of our experience with the Fraglets language, an algorithmic chemistry designed for the automatic synthesis and evolution of communication protocols. Although Fraglet programs can easily be made robust to instruction loss, they are not robust to random mutations in general, leading most of the times either to inert programs or to programs that grow unbounded (elongation problem). We summarize our on-going efforts to make the language more robust and evolvable, and then report some promising recent results, in which an energy-based resource control method is able to keep programs within a feasible operation range.

Short bio: Lidia Yamamoto holds a Doctoral degree in Computer Science from the University of Liege (Belgium, 2003), a Master degree in Communication Systems and Networks from the Technical University of Madrid (Spain, 1995), and a Bachelor degree in Computer Science from the State University of Campinas (Brazil, 1991). She is currently a postdoctoral researcher in the Computer Networks Group of Prof. Christian Tschudin at the University of Basel (Switzerland, 2004-). Her main research interests are artificial chemistries, genetic programming, and biologically-inspired computing.

More information: http://cn.cs.unibas.ch/people/ly/

Selected Security and Privacy Schemes for Wireless Sensor Networks: CDA and Secure Code Update

Abstract: The talk deals with security solutions for the protection of wireless sensor networks. After introducing a threat model for wireless sensor networks we discuss possibilities for end-to-end confidentiality. We introduce and compare various solutions belonging to the class of concealed data aggregation (CDA) schemes. At the end of the first part of the talk we show some application examples in the areas ITS and mHealth. The second part of the talk is introducing secure code update based on T-time signatures and fountain codes.

Short bio: Dirk Westhoff received the Ph.D. degree in computer science in 2000 and in 2007 his postdoctoral lecture qualification entitled 'Security and Dependability Solutions for 4G Wireless Access Networks', both from the Distance University of Hagen. Since 2001 he is at NEC Europe Ltd. R&D Network Laboratories in Heidelberg, Germany, currently as a chief researcher. Recently Dirk Westhoff has been strongly involved in the definition and launching phases of the European projects UbiSec&Sens, SENSEI and WSAN4CIP. He is co-founder of the ESAS (European Workshop on Security in Ad Hoc and Sensor Networks) series published by Springer. He has more than 50 peer-reviewed publications in network security and distributed system's security and he holds six patents. He has been involved in the TPC of several ACM and IEEE workshops and conferences and he is a member of the Steering Committee of the ACM WiSec. His research interests include wireless security, ad hoc and sensor network security, and many other security and privacy aspects of distributed mobile communication.

Secure and Usable Device Pairing

Abstract: "Secure Device Pairing" is the process of bootstrapping a secure channel between two or more previously unassociated personal devices over a (usually wireless) human-imperceptible communication channel. Lack of prior security context and absence of common trust infrastructure open the door for so-called "Man-in-the-Middle" (or "Evil Twin") attacks. Mitigation of these attacks requires user involvement in the device pairing process. Prior research yielded a number of interesting methods utilizing various auxiliary human-perceptible channels, e.g., visual, acoustic and tactile. These methods engage the user in authenticating information exchanged over human-imperceptible channels, thus countering attacks and forming the basis for secure device pairing.

This talk starts by summarizing notable secure device pairing techniques, comparing and contrasting their advantages, shortcomings and limitations. We then present the first comprehensive and comparative evaluation of these methods. Our results identify methods best-suited for a given combination of devices and human abilities. This research direction is both important and timely, since it sheds light on usability in one of the very few settings where a wide range of users are confronted with security. We conclude with some unresolved issues and potential avenues for future research.

Short bio: Gene Tsudik is a Professor in the Department of Computer Science at the University of California, Irvine (UCI). He obtained his PhD in Computer Science from USC in 1991 for research on firewalls and Internet access control. Before coming to UCI in 2000, he was a Project Leader at IBM Zurich Research Laboratory (1991-1996) and USC Information Science Institute (1996-2000). Over the years, his research interests included: routing, firewalls, authentication, mobile networks, secure e-commerce, anonymity, group communication, digital signatures, key management, mobile ad hoc networks, as well as database privacy and secure storage. He is currently serving as the Director of Secure Computing and Networking Center (SCONCE) at UCI and the Vice-Chair for Graduate Studies in the Computer Science Department. In January 2009, he was appointed Editor-in-Chief of ACM Transactions on Information and Systems Security (TISSEC).

More information: http://www.ics.uci.edu/~gts/

Virtual Data Storage Protocol for Mobile Devices

Abstract: We propose a new block-level network storage protocol, internet Advanced Technology Attachment (iATA) as a solution to counter the storage limitation issue in consumer electronics like mobile devices. With iATA, a mobile appliance is able to access and control the ATA storage devices natively through TCP/IP network from anywhere and at anytime as if the storage devices are attached locally. We will describe the concept, design and implementation consideration pertaining the iATA protocol. We will also be explaining about the experiment that was performed to investigate the optimal performance value of iATA parameter on wireless network environment and proposed as a default value in iATA protocol. Based on the benchmark experiments and application exploitation, we strongly believe that iATA as a light-weight protocol is efficient and cost-effective to be used as a storage network protocol on a resource limited device that utilizes common-off-the-shelf storage hardware and existing IP infrastructure.

Short bio: Hyotaek Lim received his B.S. degree in Computer Science from Hongik University in 1988, the MS degree in computer science from POSTECH and the PhD degree in computer science from Yonsei University in 1992 and 1997, respectively. From 1988 to 1994, he had worked for Electronics and Telecommunications Research Institute as a research staff. Since 1994, he has been with Dongseo University, Korea, where he is currently a professor in the Division of Computer and Information Engineering. His research interests include ubiquitous and mobile networking, storage area networks, and network management.

New Approaches in Network Management - The Concept of Economic Traffic Management (ETM)

Abstract: The Internet traffic is still doubling approximately every 18 month; and up to 80% of this traffic is stemming from Peer-to-Peer applications. This traffic is created by so-called overlay applications. Since the available bandwidth of end-nodes attached to the network is also increasing, overlay-based applications will become even more interesting and the diversity of such applications will increase. Therefore, a slow paradigm shift is happening: from services offered in a centralized manner to services offered by end-nodes.

Thus, for today's Telecommunication Service Providers (telco) and Internet Service Providers (ISP) this issue leads to dramatic consequences, since existing control and network management schemes for traffic stemming from overlay-based applications are not sufficient any more. Therefore, the use of new mechanisms is studied based on incentives for controlling and managing network traffic of overlay applications in the Internet in a full decentralized manner. Initial results have shown that such management mechanisms, termed Economic Traffic Management (ETM) mechanisms, do have the important property of scalability with respect to the number of players. To support such mechanisms in the protocol architecture of the Internet respective design steps have been undertaken to integrate ETM mechanisms smoothly into today's networking infrastructure.

Short bio: Prof. Dr. Burkhard Stiller chairs the Communication Systems Group CSG, Department of Informatics IFI at the University of Zürich UZH. He holds a Computer Science Diplom and a Ph.D. degree of University of Karlsruhe, Germany. During his research locations at the Computer Laboratory, University of Cambridge, U.K., the Computer Engineering and Networks Laboratory TIK, ETH Zürich, Switzerland, and the University of Federal Armed Forces, Munich, Germany his main research interests cover, including current CSG topics, charging and accounting of Internet services, economic management, systems with a fully decentralized control (P2P), telecommunication economics, and biometric management systems.

More information: http://www.tik.ee.ethz.ch/~stiller/

Controlling Wireless Access Networks: Flexibility, Reliability, and Incentives

Abstract: I discuss three interrelated issues that I consider important for the development of ubiquitous access networks. Flexibility refers to adding sufficient intelligence in the system that allows network providers to select different target objectives for operating the network. This is necessary since different providers have different operational requirements, as do different applications and users. As a specific example, I discuss how to support flexibility for joint channel selection and topology control in wireless mesh networks, with the support of different target objectives that include maximizing the aggregate throughput, fairness, and redundancy. Reliability refers to supporting a continuous level of service in time and space. Both proactive and reactive mechanisms are necessary to support reliability. Proactive mechanisms involve adding redundancy, hence additional resources, through e.g. multipath routing and encoding. Specifically, I discuss issues and requirements related to multipath routing metrics. Reactive mechanisms involve identifying failures and security attacks, and taking corrective actions. Finally, I discuss self-induced incentives where the improvements of performance motivate cooperation. This is unlike monetary or credit-based and reputation mechanisms that require accounting and enforcement of mechanisms to induce cooperation. As a specific example I discuss incentives for supporting handover, which help improve reliability in space.

Short bio: Vasilios Siris obtained the Diploma in Physics (1990) from the National and Kapodistrian University of Athens, the M.S. in Computer Science (1992) from Northeastern University, Boston, USA, and the Ph.D. in Computer Science (1998) from the University of Crete. Since 2009 he is an Assistant Professor at the Department of Informatics of the Athens University of Economics and Business. From 2002 until January 2009 he was an Assistant Professor at the Department of Computer Science of the University of Crete. He is a Research Associate at the Institute of Computer Science of the Foundation for Research and Technology – Hellas (FORTH), with which he collaborates since 1993. In the Spring of 2001 he was a Visiting Researcher at the Statistical Laboratory of the University of Cambridge, and during the Summer of 2001 and 2006 he was a Visiting Researcher at the research laboratories of British Telecommunications (BT), both in the UK.

His current research interests include resource management and traffic control in wired and wireless networks, traffic measurement and analysis for monitoring quality of service and intrusion/anomaly detection, and technology and architecture of mobile and pervasive communication systems. A key direction in his research is the combination of analytical methods and techniques, with the prototype implementation and evaluation of these methods in actual systems.

He has over 70 publications in international peer reviewed journals and conferences, in addition to two patents in the area of resource management in wireless networks. He is a Technical Program Committee member of many international conferences, and is active in the organization of conferences, including the 10th IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks - WoWMoM 2009 (General Co-Chair), the 6th International Conference on Wired/Wireless Internet Communications - WWIC 2008 (Technical Program Committee Co-Chair), and the 3rd European Conference on Computer Network Defense - EC2ND 2007 (General Co-Chair). He is/was the Principal Investigator and Coordinator for many research and development projects funded by the European Commission, the Greek government, and the industry.

More information: http://www.ics.forth.gr/~vsiris/

Wireless Communication Needs Dynamics!

Abstract: Wireless Communication can be significantly improved by introducing aggressive dynamic adaptation to the actual conditions. This general rule will be demonstrated using three case studies from the area of WLAN- type Wireless Access Networks: the OFDMA transmission, discovery of alternative Access Points in WLANs, and the emerging Cognitive Radio approaches.

Short bio: Adam Wolisz received the Diploma in Engineering, Ph.D., and Habilitation degrees from the Silesian University of Technology, Gliwice, Poland, in 1972, 1976, and 1983, respectively. After a period with Polish Academy of Sciences (until 1990) and GMD-Fokus, Berlin, Germany (1990–1993), he joined Technische Universität Berlin, in 1993, where he is the Chaired Professor for Telecommunication Networks and the Executive Director of the Institute for Telecommunication Systems. He is also an Adjunct Professor with the Department of Electrical Engineering and Computer Science, University of California, Berkeley. His research interests are in architectures and protocols of communication networks. He is currently focusing mainly on wireless/mobile networking and sensor networks.

More information: http://www.tkn.tu-berlin.de/~wolisz/wolisz.html

Advances in Cooperative Wireless Communications

Abstract: In the early days of wireless communications the research community used to view multipath-induced dispersion as an undesirable propagation phenomenon, which could only be combatted with the aid of complex channel equalizers. The longer the Channel Impulse Response (CIR) was, the more complex the channel equalizer became. However, provided that the complexity of a sufficiently high-memory channel equalizer was affordable, the receiver could benefit from the fact that the individual propagation paths faded independently. To leaborate a little further, even if one of the paths was experiencing a high attenuation, there was a good chance that some of the other paths were not, which led to a potential diversity gain.

However, if the channel does not exhibit several independently fading paths, techniques of artificially inducing diversity may have to be sought. A simple option is to employ a higher direct-sequence spreading factor, which results in a higher number of resolvable multipath components and hence in an increased diversity gain. Naturally, this is only possible if either the available bandwidth may be extended according to the spreading factor or the achievable bitrate is reduced by the same factor. A whole host of classic diversity combining techniques may be invoked then for recovering the original signal.

As a design alternative, we commence by classifying the different Multiple-Input Multiple-Output (MIMO) schemes while considering the attainable diversity gains, multiplexing gains and beamforming gains. Following a brief classification of different MIMO schemes, where the different MIMO schemes are categorised as diversity techniques, multiplexing schemes, multiple access arrangements and beamforming techniques, we introduce the family of multi-functional MIMOs. These multi-functional MIMOs are capable of combining the benefits of several MIMO schemes and hence attaining an improved performance in terms of both their Bit Error Ratio (BER) as well as throughput. The multi-functional MIMOs family combines the benefits of space-time coding, Bell Labs Layered Space-Time scheme as well as beamforming. We also introduce the idea of Layered Steered Space-Time Spreading that combines the benefits of Space-Time Spreading, V-BLAST and beamforming with those of the generalised Multi-Carrier Direct Sequence Code Division Multiple Access. Additionally, we compare the attainable diversity, multiplexing and beamforming gains of the different MIMO schemes in order to document the advantages of the multi-functional MIMOs over conventional MIMO schemes.

However, in the presence of shadow-fading the now classic co-located MIMO elements are incapable of providing multiple independently faded replicas of the transmitted signal. This problem may be corcumvented by employing relaying, distributed space-time coding or some other cooperation-aided procedure, which is the subject of this lecture. One could also view the benefits of decode-and-forward based relaying as receiving and then flawlessly regenerating and re-transmitting the original transmitted signal from a relay - provided of course that the relay succeeded in error-freely detecting the original transmitted signal.

This lecture reviews the current state-of-the-art and proposes a number of novel hybrid relaying and cooperation techniques. An important related issue is the availability or the absence accurate channel information, which leads to the concept of coherent versus non-coherent detection at the realys and at the destination. We will demonstrate the benefits of non-coherent cooperative solutions and conclude with a number of research-challenges in the areas of sophisticated near-capacity irregular channel codes, successive multiple relaying used for eliminating the relays' multiplexing loss, the related initial synchronization issues, etc in the interest of creating low-power 'green' wireless systems.

Short bio: Lajos Hanzo received his Master degree in electronics from the Technical University of Budapest in 1976, his doctorate in 1983 and his Doctor of Sciences (DSc) degree in the UK in 2004. He is a Fellow of the Royal Academy of Engineering (FREng). He co-authored 17 IEEE Press - John Wiley books totalling in excess of 10 000 pages on mobile radio communications, published in excess of 900 research papers, organised and chaired major IEEE conferences, and has been awarded a number of distinctions. Lajos is also an IEEE Distinguished Lecturer and a Fellow of both the IET/IEE and IEEE. He is the Editor-in-Chief of the IEEE Press. For further information on research in progress and associated publications please refer to http://www-mobile.ecs.soton.ac.uk