22nd International Conference on Distributed Computing and Networking
Jan 5th-8th, 2021
Nara, Japan Virtual Conference


January 5, 8:00-9:00 (UTC+9)

Network Decomposition and Distributed Derandomization

Abstract: This keynote talk will provide an overview of a recent line of work [Rozhoň and Ghaffari at STOC 2020; Ghaffari, Harris, and Kuhn at FOCS 2018; and Ghaffari, Kuhn, and Maus at STOC 2017], which presented the first efficient deterministic network decomposition algorithm as well as a general derandomization result for distributed graph algorithms. Informally, the derandomization result shows that any (locally-checkable) graph problem that admits an efficient randomized distributed algorithm also admits an efficient deterministic distributed algorithm. These results resolve several central and decades-old open problems in distributed graph algorithms.

Mohsen Ghaffari

ETH Zurich, Switzerland


Mohsen Ghaffari is an Assistant Professor in the Computer Science department of ETH Zurich. Before joining ETH in 2016, he received his PhD from MIT. Mohsen’s research is focused on distributed algorithms and parallel algorithms, and his work on these areas has been honored by several best paper awards (at conferences such as PODC, SODA, DISC, and ICALP), the 2017 ACM-EATCS Principles of Distributed Computing dissertation award, and an honorable mention of ACM’s 2017 Doctoral Dissertation award.

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KEYNOTE Speech 2

January 5, 11:00-12:00 (UTC+9)

5G evolution and 6G

Abstract: 5G commercial service was launched globally. Study and development for technologies toward evolution of 5G are ongoing taking into account issues in initial 5G and coming market needs. Research on beyond 5G/6G initiated in the world. 5G is expected to provide new value as a basic technology supporting future industry and society, along with artificial intelligence (AI) and the Internet of Things (IoT), as well as further upgrading of the multimedia communication services with its technical features such as high speed, high capacity, low latency, and massive connectivity. In the future, while 5G is expected to be utilized in various industrial fields, conducting research and development aiming at the further future of 5G is desirable by looking at future market trends, needs, social problems, and technological evolution. The mobile communication system has been evolving technically every decade, while the services of mobile communications have changed greatly in cycles of approximately 20 years. Therefore, the "Third Wave" initiated by 5G is expected to become a larger wave through the "5G evolution and 6G", and will support industry and society in the 2030s. NTT DOCOMO published the white paper on "5G evolution and 6G" in January, 2020 and updated in July, 2020. In this presentation, contents of the white paper and our latest study results on "5G evolution and 6G" will be explained.

Takehiro Nakamura

Senior Vice President, General Manager of 6G Laboratories, NTT DOCOMO, INC., Japan


Mr. Takehiro Nakamura joined NTT Laboratories in 1990. He is now SVP and General Manager of the 6G Laboratories in NTT DOCOMO, INC. Mr. Nakamura has been engaged in the standardization activities for the W-CDMA, HSPA, LTE/LTE-Advanced and 5G at ARIB in Japan since 1997. He has been the Acting Chairman of Strategy & Planning Committee of 5G Mobile Communications Promotion Forum (5GMF) in Japan since October 2014. Mr. Nakamura has also been contributing to standardization activities in 3GPP since1999, including as a contributor to 3GPP TSG-RAN as chairman from April 2009 to March 2013. He is also very active in standardization of C-V2X/Connected Car in ARIB and ITS Infocommunications Forum in Japan. He is now a leader of Cellular System Task Group of ITS Info-communications Forum.

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KEYNOTE Speech 3

January 5, 18:40-19:40 (UTC+9)

Asymmetric Distributed Trust

Abstract: Quorum systems are a key abstraction in distributed fault-tolerant computing for capturing trust assumptions. They can be found at the core of many algorithms for implementing reliable broadcasts, shared memory, consensus and other problems. This talk introduces asymmetric Byzantine quorum systems that model subjective trust. Every process is free to choose which combinations of other processes it trusts and which ones it considers faulty. Asymmetric quorum systems strictly generalize standard Byzantine quorum systems, which have only one global trust assumption for all processes. The talk presents also several protocols that tolerate Byzantine faults with asymmetric trust, such as shared-register implementations and reliable Byzantine broadcasts. Consensus is arguably one of the most important notions in distributed computing and also relevant for practical systems. We also showhowto realize consensus protocols with asymmetric trust, illustrating our approach for protocols in partially synchronous systems and for asynchronous protocols that use randomization with asymmetric trust. Asymmetric quorum systems offer a way to understand some ideas behind the Ripple and Stellar blockchain protocols, which aim at relaxing symmetric trust assumptions and permit flexible trust. The presentation is based on joint work with Björn Tackmann and Luca Zanolini.

Christian Cachin

University of Bern, Switzerland


Christian Cachin is a professor of computer science at the University of Bern, where he leads the cryptology and data security research group since 2019. Prior to that he worked for IBM Research - Zurich during more than 20 years. He has held visiting positions at MIT and at EPFL and has taught at several universities during his career in industrial research. He graduated with a Ph.D. in Computer Science from ETH Zurich in 1997. He is an ACM Fellow, an IEEE Fellow, recipient of multiple IBM Outstanding Technical Achievement Awards, and has also served as the President of the International Association for Cryptologic Research (IACR) from 2014-2019. With a background in cryptography, he is interested in all aspects of security in distributed systems and especially in cryptographic protocols, consistency, consensus, blockchains, and cloudcomputing security. He has developed many cryptographic protocols, particularly for achieving consensus and for executing distributed cryptographic operations over the Internet. In the area of cloud computing, he has contributed to standards in storage security and developed protocols for key management. He co-authored a textbook on distributed computing titled “Introduction to Reliable and Secure Distributed Programming”. While at IBM Research he made essential contributions to the development of Hyperledger Fabric, a blockchain platform aimed business use.

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KEYNOTE Speech 4

January 6, 8:00-9:00 (UTC+9)

Building next-generation healthcare systems using distributed machine learning

Abstract: Medicine stands apart from other areas where AI can be applied. While we have seen advances in other fields with lots of data, it is not the volume of data that makes medicine so hard, it is the challenges arising from extracting actionable information from the complexity of the data. It is these challenges that make medicine the most exciting area for anyone who is really interested in the frontiers of machine learning – giving us real-world problems where the solutions are ones that are societally important and which potentially impact on us all. Think Covid 19! In this talk I will show how AI and machine learning are transforming medicine and more generally healthcare and how medicine is driving newadvances in machine learning, including newmethodologies in automated machine learning, interpretable and explainable machine learning, dynamic forecasting, causal inference and distributed machine learning. I will also discuss our experiences in implementing such AI solutions nationally, in the UK, in order to fight the current Covid 19 pandemic as well as how they can be adapted for international use.

Mihaela van der Schaar

University of Cambridge and University of California Los Angeles


Mihaela van der Schaar is the John Humphrey Plummer Professor of Machine Learning, Artificial Intelligence and Medicine at the University of Cambridge, a Fellow at The Alan Turing Institute in London, and a Chancellor’s Professor at UCLA. Mihaela was elected IEEE Fellow in 2009. She has received numerous awards, including the Oon Prize on Preventative Medicine from the University of Cambridge (2018), a National Science Foundation CAREER Award (2004), 3 IBM Faculty Awards, the IBM Exploratory Stream Analytics Innovation Award, the Philips Make a Difference Award and several best paper awards, including the IEEE Darlington Award. Mihaela’swork has also led to 35 USA patents (many widely cited and adopted in standards) and 45+ contributions to international standards for which she received 3 International ISO (International Organization for Standardization) Awards. In 2019, she was identified by National Endowment for Science, Technology and the Arts as the most-cited female AI researcher in the UK. She was also elected as a 2019 "Star in Computer Networking and Communications" by N2Women. Her research expertise spans signal and image processing, communication networks, network science, multimedia, game theory, distributed systems, machine learning and AI. Mihaela’s research focus is on machine learning, AI and operations research for healthcare and medicine.

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KEYNOTE Speech 5

January 6, 18:00-19:00 (UTC+9)

Opportunities and challenges in real-world IoT



Lukas Kencl

Electrolux, Czech Republic


Lukas Kencl obtained a PhD. degree in Communication Networks from EPFL, Switzerland (2003) and MSc. in Computer Science from Charles University, Prague (1995). Since 2016 he is Head of Global Connectivity Architecture at the Electrolux Group Technology Organization (GTO), where he is responsible for architecture and cybersecurity leadership and R&D contributions in the fields of networking, cybersecurity, software/firmware, cloud computing and data analytics, as part of the company's growing participation in the IoT ecosystem. He leads a team of architects designing innovative systems for connected consumer appliances, represents Electrolux in standardizaton efforts and manages the GTO Prague site. He also maintains affiliation to Czech Technical University in Prague (CTU), where he supervises multiple doctoral students. Previously, he was Director of the R&D Centre for Network Applications (RDC) at FEE CTU, Prague (2007-16), Senior Researcher at Intel Research, Cambridge, UK (2003-6) and a Pre-Doc at IBM Research-Zurich (1999-2003). Dr. Kencl is co-inventor of multiple networking patents and co-author of more than 60 publications in the networking domain. He was General Chair of IFIP Networking 2012 and TPC Chair of IGBSG 2016 and frequently acts at TPC member at various IEEE and ACM conferences.

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KEYNOTE Speech 6

January 7, 8:00-9:00 (UTC+9)

Autonomous Distributed Systems of Myopic Mobile Robots with Lights

Abstract: The cooperation of swarming autonomous mobile robots has received significant interests in recent years. The common goal of research on it is to clarify the minimum capabilities for robots to achieve a given task. Thus, algorithms for mobile robots have been considered on a theoretical model with negative assumptions about each robot capabilities. Concerning the assumptions, each robot is identical (i.e., all robots run the same algorithm), anonymous (i.e., each robot has no IDs to distinguish two robots), oblivious (i.e., each robot has no memory to record past situation) and silent (i.e., each robot has no direct means of communication). In the initial model described above, because of fundamentally weak capabilities, it is known that most tasks cannot be solved without some additional assumptions even if the model considers the unlimited visibility. However, we may not need to assume completely oblivious robots considering their implementations on real devices because persistent memory is widely available. Thus, recently, luminous robots have attracted attention in order to improve robot capability. A luminous robot maintains a non-volatile visible light, and emits the chosen light color among a set of colors to other robots. That is, a luminous robot uses the light to memorize its state and communicate with other robots. On the other hand, for the assumption of unlimited visibility of the initial model, each robot has a too strong observation device. Therefore, several recent studies focus on myopic robots to consider the implementation of the robot system. A myopic robot has limited visibility, i.e., it can take a snapshot only within a certain fixed distance. In this talk, we consider myopic robots with lights as a more realistic model and briefly show some recent results on the model.

Sayaka Kamei

Graduate School of Advanced Science and Engineering, Hiroshima University, Japan


Sayaka Kamei received the B.E., M.E., and D.E. degrees in computer science from Hiroshima University in 2001, 2003, and 2006, respectively. She worked at the Tottori University of Environmental Studies and Hiroshima University as an assistant professor from 2006-2008 and 2008-2012, respectively. Now, she is an associate professor of the Graduate School of Advanced Science and Engineering, Hiroshima University. Her research interests include distributed algorithms. She is a member of the IEEE, IEEE Computer Society, ACM, IEICE, and IPSJ.

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