News archive, 2023
Gautham Rangasamy makes transistors 4x better
Published: 2023-11-27
Title of thesis: Vertical III-V Nanowire Tunnel Field-Effect Transistors: A Circuit Perspective. Link to thesis in LU Research...
Title of thesis: Vertical III-V Nanowire Tunnel Field-Effect Transistors: A Circuit Perspective.
Link to thesis in LU Research Portal:
Defence: Friday December 15th, 09:15, Lecture Hall E:B, building E..
Describe your research in a popular science way
The convenience and improvement in quality of our daily life is enabled by terabytes in data storage, data processing and data communication enabled by trillions of transistors, consuming terawatt-hours of electricity. With the emergence of new fields in AI, Neuromorphic Computing, Quantum Computing, Internet of Things, to name a few, we can be rest assured of further increase in electronic systems in our daily life. This puts us in an fascinating time, quasi - science fiction even, as we speculate on the enormous potential these fields would bring. The caveat, of course, is the increase in the data produced and the accompanying energy consumption. As all the electronics system are made with a basic building block called transistors, one way of mitigating the increasing power consumption is by making them more efficient. My thesis work explores this possibility by using quantum tunneling based transistors. I am happy to report that we were able to achieve record performance transistors enabling more energy efficient systems.
Please complement with a relevant, or your favorite, graph/illustration (that is ok to publish from an IPR perspective) together with a caption of 10-30 words.
Top view of the fabricated tunnel field-effect transistor. We were able to increase the current by 400% compared to state-of-the-art devices.
What made you want to pursue a PhD?
It might be a cliché, but I just wanted to make the world a bit better and maybe also make myself a bit better person in the process. I figure I did manage that in the end thanks to my supervisors, my colleagues and above all, my students.
What is the most fascinating or interesting with your thesis subject?
I work with different materials systems, trying to optimize their composition for the best transistor performance. It was akin to playing hide-and-seek at a nanometre scale and overall a fascinating puzzle to solve!
Do you believe some results from your research will be applied in practice eventually? And if so, how / how?
I believe breaching the threshold of 1 µA/µm current with SS < 60 mV/dec is the most important result of my thesis work. As an optimist, I feel this would find applications in low power electronics!
What are your plans?
After my PhD, I'm heading to Germany to join a startup. We're working on making quantum computers happen!
Link to the article Gautham Rangasamy makes transistors 4x better
Haorui Peng tames the cloud
Published: 2023-11-16
Title of thesis: Taming Cloud Integrated Systems in the Wild.
Link to thesis i LU Research Portal:
https://portal.research.lu.se/en/publications/taming-cloud-integrated-systems-in-the-wild
Defence: Friday 2023-12-08, 09:15, Lecture Hall E:1406,...
Title of thesis: Taming Cloud Integrated Systems in the Wild.
Link to thesis i LU Research Portal:
https://portal.research.lu.se/en/publications/taming-cloud-integrated-systems-in-the-wild
Defence: Friday 2023-12-08, 09:15, Lecture Hall E:1406, building E, Ole Römers väg 3.
Describe your research in a popular science way
In the era of digital transformation, the cloud has evolved from a mere atmospheric phenomenon to a revolutionary technology reshaping our daily lives. Acting as a shared repository of computing power, the cloud operates on a "pay-as-you-go" model, akin to a communal library for computers, offering accessibility to sophisticated software and substantial data storage without the need for extensive hardware ownership.
While widely used, the cloud's integration isn't seamless, often resulting in less-than-optimal user experiences?lagging Google Docs or delayed responses in Xbox Cloud Gaming are familiar instances. My research delves into the intersection of cloud technology and complex industrial systems, focusing on Cloud RAN and Cloud Control Systems. These innovations transfer computational tasks from traditional setups to the cloud, promising efficiency but also introducing challenges.
The critical question my research tackles is twofold: Can we effectively integrate industrial systems with the cloud, and how can we optimize these integrations, acknowledging the inherent imperfections in cloud and network communications?
Identifying the shared nature of the cloud and latency as primary challenges, I steer away from the conventional approach of speeding up the cloud or networks, which often lies beyond our control. Instead, my work concentrates on adapting our systems to thrive within these limitations. The goal is to ensure that, despite the imperfections in the cloud and network, our cloud integrated systems operate as efficiently as possible, emphasizing optimization from the system's perspective.
What is the most fascinating or interesting with your thesis subject?
The cloud, with its seamless software consumption and deployment capabilities, is inherently intriguing. Yet, the ?unknown? aspects of the cloud and intermediary networks present a significant hurdle for traditional industries. Integrating the cloud into an industrial system goes beyond a simple addition; it necessitates a paradigm shift in system perspective and deployment strategies, accompanied by the nuanced handling of novel challenges introduced by the cloud. Each system reacts uniquely to this integration, influenced by a myriad of interacting factors. Despite the complexities, I firmly believe in the inevitable shift of industries towards cloud integration, and my thesis subject aims to serve as a bridge, facilitating this transformative journey.
Do you believe some results from your research will be applied in practice eventually? And if so, how / how?
Yes, I am confident that my research holds practical applicability. While it might not involve a direct implementation of the frameworks I developed into an existing system, I believe my work introduces a novel approach to thinking, analyzing, and implementing cloud integration in industrial systems. I do believe that this perspective is valuable and has the potential to significantly contribute to ongoing industrial digital transformations.
What are your plans?
I plan to continue my career within my current department as a research engineer, with a primary focus on developing network and application infrastructures for the next generation of communication systems. Additionally, I will continue my exploration into the integration of cloud technologies with these systems.
Link to the article Haorui Peng tames the cloud
Iman makes cell phone signals clearer
Published: 2023-11-02
Reconfigurable receiver front-ends for advanced telecommunication technologies
Iman Ghotbi defends his thesis November 24th, 09:15 in E:1406.
Zoom link:
https://lu-se.zoom.us/j/64532196838
Link to thesis in LUCRIS:
Describe your research in a popular science way
Have you ever been in a stadium, struggling to communicate amid deafening noise? Imagine having the power to establish a clear channel, immune to interference, with someone right beside you. While my thesis doesn't promise superpowers, it does focus on enhancing your cellphone's capabilities.
Just as crowded venues disrupt our conversations, cellphones face challenges delivering multimedia experiences in congested environments. Imagine the near future, where you use your cellphone for 3D augmented reality or share real-time events with thousands of others simultaneously. This data load is staggering.
How can cellphones maintain seamless communication amidst interference? We can't shout louder, just as your vocal cords can't overpower the crowd?s noise. Instead, semiconductor technology allows cellphones to reject unwanted signals. Our research designs selective filters to quell interferences, ensuring clear, high-speed, and energy-efficient communication. These filters adapt to changing interference levels, making them crucial for modern wideband technologies like 6G.
What made you want to pursue a PhD?
From the very beginning of my undergraduate studies, I found analog and RF electronic circuit design to be an endlessly fascinating field. The complexity of working with semiconductor technology, electromagnetics, and circuit theory all in one package sparked my curiosity and ignited my passion for innovation. What truly excited me about this area of study was the satisfaction of seeing a concept I had designed and engineered, overcome uncertainties, and perform precisely as intended in the real world.
Pursuing a PhD was a natural progression of this passion. It provided me with a golden opportunity to gain a profound understanding of the subject, honing my engineering skills, and mastering the art of communicating science. Furthermore, it provided me with the opportunity to embrace the roles of both a researcher and an educator, a path that I was eager to embark on.
What is the most fascinating or interesting with your thesis subject?
As the title of the thesis indicates, the most intriguing aspect of my thesis is the development of reconfigurable CMOS solutions. These solutions can flexibly adjust to a wide range of gains, frequencies, bandwidths, and interference rejection. This adaptability is crucial in enabling 5G/6G receivers to operate efficiently in diverse conditions. This is particularly important when implementing broadband software defined radios and spectrum-aware cognitive radios, which are universal solutions for multi-standard multi-band receivers.
Do you believe some results from your research will be applied in practice eventually? And if so, how / how?
I firmly believe that the circuit solutions we developed in this PhD project have the potential to enhance the power efficiency, tolerance, and noise performance of CMOS wideband receiver front-ends. This contribution becomes even more significant when we consider the challenges of realizing low-power and highly reconfigurable receivers that are essential for the centimetric frequency band of the 6G spectrum.
What are your plans?
I plan to continue my academic journey as a researcher and teacher.
Link to the article Iman makes cell phone signals clearer
Xuhong Li received best Journal paper award.
Published: 2023-10-04
Postdoctoral researcher Xuhong Li received the IEEE Sweden VT-COM-IT Joint Chapter Best Student Journal Paper Award at the 2023 Swedish Communication Technologies Workshop previous week. The award is given to the best paper published by a PhD...
Postdoctoral researcher Xuhong Li received the IEEE Sweden VT-COM-IT Joint Chapter Best Student Journal Paper Award at the 2023 Swedish Communication Technologies Workshop previous week. The award is given to the best paper published by a PhD student in Sweden during 2021-2022 in the area of communications systems and theory, Information theory, networking, signal processing, and related areas.
Detection and estimation of multipath components in wireless channels have always been seen as a tricky and highly complex problem. The area has traditionally been used for radio channel modeling but in recent times it has become very important in the area of radio-based positioning. In the paper Xuhong Li has developed and demonstrated a new approach for sequential estimation and tracking of multipath components. The latter is very important for positioning where multipath components from several snapshots typically are used for the positioning task. The developed algorithm has relatively low complexity, especially in comparison to other state of the art methods, while it provides superior performance, especially in low and medium SNR regions. The developed framework offers many advantages and can be an important step towards real-time highly accurate radio-based positioning.
X. Li, E. Leitinger, A. Venus and F. Tufvesson, "Sequential Detection and Estimation of Multipath Channel Parameters Using Belief Propagation," in
IEEE Transactions on Wireless Communications, vol. 21, no. 10, pp. 8385-8402, Oct. 2022, doi: 10.1109/TWC.2022.3165856.
https://arxiv.org/abs/2109.05623
Link to the article Xuhong Li received best Journal paper award.
Zhongyunshen creates new transistor technology
Published: 2023-10-02
Zhongyunshen Zhu defends his thesis Friday, October 13th in lecture hall E:1406, 09:15. Link to thesis. Zoom link. Zoom ID: 64195800022.
Describe your research in a popular science way
Transistors are the building blocks for the advanced chips in...
Zhongyunshen Zhu defends his thesis Friday, October 13th in lecture hall E:1406, 09:15.
Link to thesis.
Zoom link. Zoom ID: 64195800022.
Describe your research in a popular science way
Transistors are the building blocks for the advanced chips in your computers and smartphones. My research mainly focuses on developing new transistor technologies based on vertical nanowires to increase the energy efficiency and functionality in the circuit system.
What made you want to pursue a PhD?
I was quite interested in semiconductor materials and electronic devices and would like to dive deeper into this research area. This mainly motivated me to pursue a PhD in this field.
What is the most fascinating or interesting with your thesis subject?
The integration of a ferroelectric gate on the 3D nanowire transistor. This leads to a new reconfigurable device with much smaller area and power consumption as well as more functions, which could be cutting edge transistors in AI technology.
Do you believe some results from your research will be applied in practice eventually? And if so, how / how?
I do believe some results from our research could be useful in practice. The fabricated transistors can work with lower power and smaller area, in line with the goal in industry and the sustainability criteria from an environmental perspective. Also, our transistors can integrate with emerging materials such as ferroelectrics, leading to reconfigurable and in-memory computing devices in a 3D nanowire geometry. This could be another interest to be applied in practice.
What are your plans?
I will continue the research on similar topics in the group.
Link to the article Zhongyunshen creates new transistor technology
Navya creates 6G transistors
Published: 2023-09-18
Name: Navya Sri Garigapati Date of dissertation: 27-09-2023 Title of thesis: Radio Frequency InGaAs MOSFETs Link to thesis:
https://portal.research.lu.se/en/publications/radio-frequency-ingaas-mosfets
Describe your research in...
Name: Navya Sri Garigapati
Date of dissertation: 27-09-2023
Title of thesis: Radio Frequency InGaAs MOSFETs
Link to thesis:
https://portal.research.lu.se/en/publications/radio-frequency-ingaas-mosfets
Describe your research in a popular science way
Transistors are the key component of today's modern wireless world; for example, their superior performance enables users to stream their favorite movies anytime and everywhere. 6G cellular networks will be introduced at the earliest by the end of this decade, and to meet these high data rates, transistors' operating frequency should be increased to a few 100's of GHz. Achieving these challenging targets with the current industry standard Si transistor technology is difficult, and the need to search for new device material and transistor design is rising. In my Ph.D., a particular transistor type, i.e., field effect transistors (FETs) made of high-electron mobility channel material, are designed and fabricated, and their high-frequency performance limits are studied.
What made you want to pursue a PhD?
Curiosity and desire to advance knowledge and expertise in the field of Nanoelectronics, especially transistor design and technology, were the reasons to become a Doctoral student.
What is the most fascinating or interesting with your thesis subject?
Radio frequency InGaAs MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) are fascinating to study because of their excellent device physics and design and fabrication challenges. If these transistors perform as they should, they will easily outperform Si RF CMOS.
Do you believe some results from your research will be applied in practice eventually? And if so, how / how?
Attempts to integrate III-V transistor technology with Si CMOS have been ongoing, allowing the industry to leverage the advantages of two different device technologies. The presented transistor designs are promising candidates to replace the Si RF CMOS front-end receiver due to their low noise and better high-frequency performance.
What are your plans?
I will work as an industrial postdoc at Hexagem, here in Lund. My research is focused on GaN FinFETs for high-power and high-frequency applications. The experience and knowledge I gained during my Ph.D. would greatly benefit the next step of my research career.
Link to the article Navya creates 6G transistors
Saketh designs compute-in-memory
Published: 2023-08-24
Saketh Ram Mamidala defends his thisis Friday, September 1st in lecture hall E:B, 09:15. Zoom link: https://lu-se.zoom.us/s/64202896244 Zoom ID: 64202896244.
External link to...
Saketh Ram Mamidala defends his thisis Friday, September 1st in lecture hall E:B, 09:15.
Zoom link: https://lu-se.zoom.us/s/64202896244 Zoom ID: 64202896244.
External link to thesis:
https://portal.research.lu.se/en/publications/vertical-iii-v-nanowires-for-in-memory-computing
Describe your research in a popular science way.
Answers to complex engineering problems are often found by simply turning to nature. The blade shape of a wind turbine was inspired by the ridges on the pectoral fins of a humpback whale and automobile windshields were inspired by the design of a spider?s web to prevent shattering. When it comes to computing, a natural comparison drawn is with the biological brain. We know that computers for a given problem, are far superior in terms of calculation speed and precision, but are they energy-efficient? With the rise of artificial intelligence (AI) and data-hungry machine learning, the energy demand on the present computing systems is only increasing.
The fundamental units that build a computer are the processor and memory. The traditional computers we use today are based on the von Neumann architecture, where the memory and processor units are separate. The physical separation poses a severe constraint on further development as the data needs to be constantly shuttled between the two units and is termed the von Neumann bottleneck. The biological brain, on the other hand, can process and store information, making it extremely energy-efficient. In this work, we propose a solution for achieving compute-in-memory in a 3D geometry using vertical nanowires.
What made you want to pursue a PhD?
Honestly, I went with the flow after my master?s. But now, as I reach the end of my Ph.D, I can safely say that if I could go back in time, I'd choose to do a Ph.D again.
Do you believe some results from your research will be applied in practice eventually? And if so, how / how?
The industry has expressed concerns about achieving scalability in both geometry and supply voltage for integrating 1-transistor-1-resistor (1T1R) devices in crossbar arrays. In this thesis, we present a potential solution that addresses these concerns. It is difficult to predict if it will be used in practice, but it is satisfying enough to know that our work is timely and may be used in some form in the future.
What are your plans?
I'll be continuing my research journey as a postdoctoral researcher at IBM-Research in Zurich, Switzerland. My primary focus will be on delving deeper into the field of neuromorphic computing. I look forward to applying the knowledge I've gained here at Lund and learning new things along the way!
Link to the article Saketh designs compute-in-memory
EIT students won design contest
Published: 2023-08-14
Elias Björk, Linus von Ekensteen Löfgren, Ben Nel and Oskar Watsfeldt have, supervised by Johan Lundgren, won the IEEE AP-S Student Design Contest within reconfigurable intelligent surfaces (RIS). Read more here:
External link to...
Elias Björk, Linus von Ekensteen Löfgren, Ben Nel and Oskar Watsfeldt have, supervised by Johan Lundgren, won the IEEE AP-S Student Design Contest within reconfigurable intelligent surfaces (RIS).
Read more here:
External link to the conference hompage.
Link to the article EIT students won design contest
Mattias Borg lands SSF Industry PhD project
Published: 2023-08-14
Mattias Borg, Associate Professor in Nanoelectronics, and Henrik Sjöland, specialist in analog circuit design, Ericsson, have started a five-year industry-PhD project in part financed by The Swedish Foundation for Strategic Research (SSF). The goal...
Mattias Borg, Associate Professor in Nanoelectronics, and Henrik Sjöland, specialist in analog circuit design, Ericsson, have started a five-year industry-PhD project in part financed by The Swedish Foundation for Strategic Research (SSF). The goal is to develop a hardware model of the human brain. Read more on page 47 here:
External link to news (Swedish).
Link to the article Mattias Borg lands SSF Industry PhD project
Xuesong gets Crafoord grant
Published: 2023-06-20
Xuesong Cai has received MSEK 1 from The Crafoods Foundation for his two-year project "Research on Propagation Channels for Terahertz Communication, Positioningand Sensing Towards 6G."
External link to The Crafoord Foundation.
Xuesong Cai has received MSEK 1 from The Crafoods Foundation for his two-year project "Research on Propagation Channels for Terahertz Communication, Positioningand Sensing Towards 6G."
External link to The Crafoord Foundation.
Link to the article Xuesong gets Crafoord grant
ClassIC gets 60 million
Published: 2023-05-31
Joachim Rodrigues, LTH, and Christian Fager, Chalmers, lead an initiative for advanced semiconductor-and electronic systems design. Behind ClassIC (Charmers-Lund Advanced Semiconductor System Design Center) are Chalmers Technical University, Lund...
Joachim Rodrigues, LTH, and Christian Fager, Chalmers, lead an initiative for advanced semiconductor-and electronic systems design. Behind ClassIC (Charmers-Lund Advanced Semiconductor System Design Center) are Chalmers Technical University, Lund University, Acconeer, Axis, Codasip, Ericsson, Saab, Quamcom, Globalfoundries, ST MIcroelectronics, and Cadence. The Swedish Foundation for Strategic Research awards the project with MSEK 60 during six years.
External link to Swedish article (Elektroniktidningen).
Link to the article ClassIC gets 60 million
Johan Lundgren is given the TLTH pedagogic award
Published: 2023-05-31
Johan comments: "To be a teacher is a complex puzzle with several important parts. There are so many aspects to discuss that all cannot possibly be addressed here. Discussions about this topic tend to be focused on various aspects of the role of the...
Johan comments: "To be a teacher is a complex puzzle with several important parts. There are so many aspects to discuss that all cannot possibly be addressed here. Discussions about this topic tend to be focused on various aspects of the role of the teacher in the classroom. I would like to emphasize this, and to also highlight the important role of the students themselves for the didactic development. I think that the interplay and interactions between teacher and students are crucial. I always try to amplify the levels of enthusiasm and engagement from both me and from the students. In order to achieve this, it is important to understand your group of students, including details of scheduling, their thoughts and future plans. It is the responsibility of the teacher to seek out this information, listen to the students, and continuously make improvements during the course. This way it is possible to create a rewarding, stimulating, and meaningful education experience."
Link to TLTH announcement (External, Swedish).
Link to the article Johan Lundgren is given the TLTH pedagogic award
Abinaya makes new transistors
Published: 2023-05-24
Why do the mobile phones today have a bad battery life? Are we just polishing up the old school transistors to quench the thirst of today?s technology? This thesis work focused towards developing unconventional low power transistors that can operate...
Date of dissertation: 26/05/2023, 09:15, E-house, room E1406.
Title of thesis: Vertical III-V Nanowire Transistors for Low-Power Electronics
Link to thesis:
Zoom:
https://lu-se.zoom.us/s/64156815501
What made you want to pursue a PhD?
Research into futuristic technology that are unavailable currently to general user was the idea that fascinated me to pursue a PhD. Developing transistors from small structures such as nanowires at the institution that is well-renowned internationally for its expertise in the corresponding research field made the project more attractive to take up on.
What is the most fascinating or interesting with your thesis subject?
In this thesis, we study the physical phenomena governing the current conduction in these devices through structural and electrical characterization and utilize the knowledge to improve their electrical performance to be competitive with the conventional transistors.
Do you believe some results from your research will be applied in practice eventually? And if so, how / how?
The results from the project provide deeper insights into the material choice and device design considerations for these novel transistor technologies that can be tuned for specific applications. These understandings could help in the future developments within the research field.
What are your plans?
My fascination for innovative technology that takes society forward combined with my interest in creative writing have made me excited about patents. I will start working as a Patent consultant at Valea in Malmö after my PhD studies.
Link to the article Abinaya makes new transistors
Hanieh designs 5G antennas
Published: 2023-05-16
Hanieh Aliakbari has used systematic, modal design to improve antenna bandwidth. She defends her thesis Wednesday, June 14th, E:1406, the E-house, 09:15.
Link to thesis.
Link to webinar (Zoom)
What is your thesis about?
Today's society relies more and more on the communications of various contents, especially in the form of data, with wireless communications taking the center stage. The most common form of wireless communications, mobile communications, is changing people?s lives over the entire world. One example is the number of smartphone users that grows by hundreds of millions every year, many of whom do not previously have access to telephony or the many opportunities and conveniences it brings. Simultaneously, due to the popularity of bandwidth-hungry streaming video apps, the traffic generated by existing devices also increases by 30-40% annually. In addition, new wireless application areas are also emerging. For example, autonomous vehicles and drones must communicate with their surroundings to avoid collisions and other incidents. To support these different complex contents in wireless networks, higher data rates are needed.
Antenna is a critical component in wireless communications networks as it has the role of sending or receiving the aforementioned data as wireless signals over the air, which eliminates the need for wires. The wireless signals propagate through the medium or channel between the antennas at the transmitter and receiver in the form of electromagnetic waves. In my research, I utilized an antenna design paradigm based on modal methods to meet the antenna requirements for modern wireless systems and achieve higher data rates. Basically, in modal analysis, an antenna?s complex response is described by the weighted sum of multiple rather simpler responses called modes, with the modes being easier to characterize. This results in a more systematic design procedure, which is different from the traditional antenna design framework that mainly relies on intuition from past design experiences and blind numerical optimization of structural parameters.
Following the demand for ever increasing data rates, the antennas in mobile communication systems are required to provide more features and higher performance. One trend is to employ advanced multi-antenna technology to provide high data rates and link reliability. In this context, the first track of my research deals with some fundamental challenges of multi-antenna design for smartphones. The second trend to provide higher data rates for wireless communication is to move towards higher frequencies such as millimeter wave (mm-wave) bands in 5G due to the much larger bandwidths available in those bands than sub-6 GHz bands. Therefore, the second track of my research investigates new concepts in integrated antennas for mm-wave wireless communications and/or radar systems using different modal theories.
Here the three different ?modes? of a conducting rectangular plate are illustrated, which could be a simplified model of a handset?s metal chassis i.e., the printed circuit board (PCB).
What is the most fascinating or interesting with your thesis subject?
Clear and intuitive explanations should be provided for various electromagnetic phenomena observed during the process of antenna design. Such insights are essential to achieve better antenna performance. The common problem in traditional antenna design strategies is that they do not directly provide useful physical insights of the radiating structure or its operating principles, and hence it is difficult to provide rigorous antenna design guidelines. On the other hand, the design strategy that I adopted to solve different antenna design problems in my thesis utilizes the concept of electromagnetic ?modes? to mitigate the previous limitations. These modes offer physical explanations to the (modal) behavior of the antenna system, which can then yield systematic guidelines for antenna design. In some special types of modal theories, analysis of arbitrary shape structures is possible. Furthermore, a predefined excitation is not required for the modal-based strategy. In contrast, excitation types and positions in traditional antenna design are found through visual inspection and analysis of excited currents of similar antennas, or by means of trial-and-error excitation placement.
What are your plans?
My passion has always been to pursue a career in academia. However, as a researcher, I have also been very interested in having close collaboration with reputable companies and solving real-world issues, as it would make a direct positive impact on society. Therefore, from last year I started working in Volvo Car Corporation (VCC) as a researcher and I am applying the knowledge that I have gained from my research studies for antenna system design, which has become a key aspect in developing the next generation of premium cars.
Link to the article Hanieh designs 5G antennas
Alexander protects encryption
Published: 2023-04-18
Alexander Nilsson has studied different ways to secure encryption algorithms in the post-quantum cryptography era. He defends his PhD thesis ?Decryption Failure Attacks on Post-Quantum Cryptography? on 11th of May, E:A, E-huset, 09:15.
What is your thesis about?
The evaluation of next generation of public-key encryption and digital signature algorithms are ongoing, with much at stake. The hope is that these algorithms will be secure for many, many years after their initial deployment. In fact they are expected to remain secure even in the face of fully developed and functional Quantum Computers (QCs). It is well known within the research community that QCs will break some of the most important and widespread algorithms that we otherwise use today. Replacements must be standardized well before QCs are realized. This field is called Post-Quantum Cryptography (PQC). The research included in this dissertation relates to cryptanalysis of several candidate PQC schemes. In one case a proposed alternative decoder is proposed for one of the schemes. Other results pertain to implementation issues of some of the new proposed schemes. Some attacks found in literature have been improved upon with new techniques. And some attacks are novel and affects the source code implementation of the schemes. We argue that our novel attacks are general and affect many different schemes and we show the applicability of the attacks by implementing them against some of them.
What made you want to pursue a PhD?
Being a scientist has always been something that just sounds right for me, even since I was little. Not to say I didn?t have other ideas when I was growing up as well, but the scholarly pursuit was always something that I came back to. The fact of the matter is that after my master, I applied for a few PhD positions which I didn?t get, most probably because I didn?t have any research idea available to sell to the hiring adviser. Instead, I got a job in the industry, which I was very happy about. I worked at this company for a year before the company was approached by Professor Thomas Johansson, asking if any employees would like to study for an industrial Ph.D. I said yes. We didn?t get the actual external funding for it until the third attempt two years later though.
Do you believe some results from your research will be applied in practice eventually? And if so, how / how?
My research has already had some level of impact on the effort of PQC standardization, mostly on the side of source code implementation but also in a lesser sense on the specification level, for some of the candidate PQC schemes. I expect that whenever the standards are being finalised our attacks will be considered and guarded against, which is a nice feeling.
What are your plans?
My current plans are to go back to my employer Advenica, who have so very generously lent me to the university. It will be nice to be able to work full time on a single project for a while. I expect and hope to continue working with cryptography for the foreseeable future.
Link to the article Alexander protects encryption
Martin secures your devices
Published: 2023-03-16
The Internet of Things requires a large number of small, inexpensive devices to be connected. To do this with a sufficient level of security is a major challenge that Martin Gunnarsson has taken on. He defends his PhD thesis ?Efficient Security...
Read more about the dissertation.
Download the thesis.
What is your thesis about?
Connected digital computing devices have spread to virtually all aspects of society. As of 2021, there are more connected things, i.e., small computers, on the internet than people. These small computers power a wide variety of things in our society, from household appliances and vehicles to power plants. One important sector that is becoming increasingly connected to the internet is manufacturing.
Industry 4.0, for example, predicts and outlines a more flexible future of manufacturing. Smaller series of custom products can be produced efficiently with distributed connected control systems without requiring complex and time-consuming retooling. Such trends in manufacturing point to a more connected, decentralized, and agile future.
The future of connected devices is scale and decentralization. Since devices are deployed at scale, they must be cheap to manufacture, deploy, and run. Wireless and battery-powered devices can decrease the cost of installation by 30-60%. Many devices being added to networks today are constrained devices, that is, devices with limited computational power, memory, and network bandwidth. Many constrained devices are also battery-powered and need to preserve energy.
Often the public is only made aware that a device is connected when a cyber attack disrupts that device's operation. The move from connected computers, servers, and networking equipment to connected Smart Manufacturing, Smart Grid, and other cyber-physical systems has moved the risks of cyber attacks from loss of capability and data to the risk of physical harm, loss of property, or even life. Technologies exist that mitigate the risk of connected IT infrastructures, and these technologies may not be suited to deployment in connected constrained devices. The limited performance of the constrained device can make such technologies too resource-intensive to be feasible. There can be thousands of sensors and actuators in a factory or a wireless sensor network, and solutions must be able to handle many deployed devices. This thesis addresses the need for efficient security protocols for new decentralized connected systems, and demonstrates that it is possible to implement and deploy secure and efficient protocols in the setting of constrained devices.
What is the most fascinating or interesting with your thesis subject?
The Internet of Things (IoT) has a poor reputation from a security aspect. An often-given reason is that IoT devices are not powerful enough to run adequate security measures. It is inspiring that my research has helped mitigate these shortfalls. I especially like working close to the hardware on low-performance devices where efficiency is critical and formal protocol verification.
How will your results be of use in the future?
Protocols we evaluated and implemented in my thesis are being deployed in products today. Our research on a security architecture based on the Digital Twin concept has been widely cited and used in further research in the field.
What are your plans?
I have a job lined up in the industry. Putting everything I have learned in academia into practice will be very exciting. I want to continue working with securing the connected devices that power our society.
Link to the article Martin secures your devices
Get your gain with Qiuyan's antennas!
Published: 2023-03-14
Wireless transmissions can be drastically improved by antennas with high gain and beam steering capability. Qiuyan Liang has investigated how such antennas can be designed in an efficient manner.
On March 24 at 9.15 she defends her PhD thesis...
Read more about the dissertation.
Download the thesis.
What is your thesis about?
Nowadays the use of wireless internet has permeated many aspects of our lives, including study, work, travel, and entertainment. These ever-more-complex contents transmitted in wireless communication networks are essentially in the form of data, and ever-increasing data rates are needed to support the content delivery. The communication of information requires a transmitter and a receiver. For example, if someone transmits information by speech or body language, then the information can be received by another person?s ears or eyes. Similarly, wireless communication also requires a transmitter and a receiver, with an antenna being a critical component in each. Antennas with large frequency bandwidth, high gain, and beam steering capability are very important for future wireless communication systems. However, it is very challenging to design antennas with low-complexity structures and high space utilization that can achieve these desired features. Base stations with fixed installations and non-stationary mobile terminals play critical roles in wireless communication networks. Therefore, this thesis focuses on the low-complexity multiband and beam-reconfigurable antenna design for the two applications.
Antennas based on partially reflective surface (PRS) can provide high gain with simple structure and low cost, which have good potential for application in future base stations. The first topic of this thesis is on enhancing two aspects of PRS antenna design, namely beam steering capability and shared-aperture antenna design. Existing PRS antennas mainly use standard reconfigurable approaches for beam steering, e.g., using reconfigurable loads on the PRSs? unit cells. The beam can be pointed towards different directions in different reconfigurable states. However, current beam-reconfigurable PRS antennas suffer from narrow coverage range, distorted beam shape and considerable gain variations over the beams in different directions, which may lead to degradation of communication quality. On the other hand, shared-aperture antenna design with PRS aims to integrate antennas working at different frequency bands into a shared space to provide high space utilization. However, existing design schemes suffer from inflexible frequency ratio (of the bands) and bulky antenna structures. Therefore, the main part of my thesis deals with the research question on how to solve the challenges encountered by PRS antennas with respect to beam reconfigurability and shared aperture designs, while maintaining low-complexity structures.
Figure 1: Base station and user device antennas in high frequency applications need to be capable of beam steering with high gain.
Besides base stations with fixed installations, wireless communication networks consist of a large number of user devices, including mobile terminals. With the rollout of 5G, terminal antennas are being developed to cover both existing and new 5G frequency bands, spanning both sub-6GHz bands and mm-wave bands. To save antenna implementation space, it is desirable to co-design and even co-locate these antennas. However, existing co-design approaches suffer from complex structure of the mm-wave antenna and low space utilization. Therefore, the other part of my thesis is about solving the research question on how to co-design the sub-6GHz and mm-wave antennas for mobile terminals for compactness and low-complexity.
How will your results be of use in the future?
Antennas have already been widely applied in practice and a larger number of antennas will be deployed in future wireless communication networks. My research provides low-complexity PRS antenna designs for base stations and co-designed antennas for mobile terminals. Therefore, I believe that the results from my research have the potential to contribute to the development of more cost-effective wireless communication networks by improving system architecture and saving installation resources.
Link to the article Get your gain with Qiuyan's antennas!
