News

Best paper award

01-06-2019
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Members of Teaching and Research Staff of AUEB's Department of Informatics received a Best Paper Award at the IEEE workshop on Economics of Fog, Edge and Cloud Computing (ECOFEC) 2019, in conjunction with IEEE INFOCOM, a conference for communications and computer systems, held in Paris from 28 April to 2 May 2019.

The paper that won the award is entitled "Economics of Investment and Use of Shared Network Infrastructures" and is co-authored by Iordanis Koutsopoulos (Associate Professor of the Department of Informatics and member of MMlab), Aggeliki Anastopoulou (PhD Candidate and member of STEcon lab) and Merkourios Karaliopoulos (postdoctoral researcher and member of MMlab).

The work deals with innovative mathematical models and economic mechanisms on how different entities (such as service providers) can invest and cooperatively build a telecommunications network infrastructure, which they can then use together to deploy services. In particular, the work demonstrates that if a network coordinator allocates to the entities the overall benefit from provisioned services in a specific way, then the entities’ selfish behavior on how they invest in the ends up in the same investment policy as the one resulting from full cooperation of the entities. This result shows that this profit allocation mechanism may be generalized and used as a means to eliminate selfish behaviors and to align them towards common interest.

Research positions available

31-05-2019
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We have two open research positions in the context of a Hellenic Foundation for Research and Innovation (HFRI) grant (CRESCENDO project). Starting date for the appointments is October 2019. The hired researchers will work in one or more of the following three areas:

Eligible for the positions are holders of an MSc degree in the field of Electrical and Computer Engineering, Informatics/Computer Science, Mathematics, or other related subject; current PhD students, who might want to work in one of the three areas as part of, or even independently of, their PhD work; young postdoctoral researchers with prior expertise and/or interest in one or more of the three areas.

Applicants should have proficient knowledge of the English language and good technical writing and communication skills. Prior experience with mathematic software packages such as MATLAB and analytical skills in any of the areas of queuing theory, game theory, optimization, algorithms will be assessed positively. Equally welcome is possible experience with data mining and analysis of large datasets.

The researchers will join the Mobile and Multimedia Lab (https://mm.aueb.gr) of the Department of Informatics, in the Athens University of Economics and Business (AUEB). The Lab is housed in the new building of AUEB, possesses excellent computational resources, and hosts one of the largest and strongest teams across Greece in the area of networking. The monthly salary will be according to the provisions of HFRI for these grants, which make allowance for added value tax and mandatory insurance expenses on the employer's side

Interested applicants should send an email expressing their interest and addressing their questions to Dr. Merkouris Karaliopoulos (mkaralio@aueb.gr) with subject line "CRESCENDO project positions" and an attached cv, by June 30th, 2019

Paper presentation at INFOCOM CryBlock workshop

24-05-2019
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Vasilios Siris presented AUEB's work on interledger smart contracts for decentralized authorization in constrained IoT environments, which was funded by H2020 project SOFIE (Secure Open Federation for Internet Everywhere), at the 2nd Workshop on Cryptocurrencies and Blockchains for Distributed Systems (CryBlock 2019), co-located with IEEE INFOCOM 2019, April 29th, 2019, Paris, France.)

You can download the paper by clicking here

Talk by Ioannis Psaras

15-04-2019
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Ioannis Psaras who is currently an EPSRC Fellow (2015-2020) and Lecturer with the E&EE Dept. at UCL, London, will give a talk on "Decentralised Edge Computing through Distributed Trust" on Tuesday, April 16th, at room 414 of the Trias Str. building of the Athens University of Economics and Business (AUEB)

Talk abstract: The Internet world is turning upside-down. In today's Internet, data is primarily flowing from data-centre servers and server farms, placed largely at the core of the network, towards the users at the edge of the network. In tomorrow's Internet, data will (primarily) be produced at the edge of the network from IoT devices, smart/autonomous vehicles, wearables, sensors and the like. This data will be of enormous volume. It has been said that each autonomous vehicle could generate tens of TBs of data per hour. The current Internet infrastructure is not prepared to accommodate this volume of data coming in from the edge. The current model of sending everything back to the cloud for processing will simply not cope with this wave of data coming from the edge. In order to get the Internet infrastructure prepared for this change, there are a number of components that need to be smoothly integrated into the current Internet architecture. At UCL, we are building solutions to address the needs of a future, privacy-preserving, IoT-dominated edge computing environment.

Talk by Vach Kompella

03-04-2019
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Dr. Vach Kompella, Vice President, Mobile Gateway R&D, Nokia (based in the Bay Area/Silicon Valley) will give a talk on Thu 4/4/2019, 16:30-18:00 in E710 (Evelpidon 47A, 7th floor)

An informal discussion will follow

Best paper award

07-01-2019
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Our paper won the best paper award at the 7th International Symposium on Security and Privacy on Internet of Things (SPIoT).

The symposium took place in conjunction with the 11th International Conference on Security, Privacy and Anonymity in Computation, Communication and Storage (SpaCCS), Melbourne, Australia, December 2018. The paper, titled "Interacting with the Internet of Things Using Smart Contracts and Blockchain Technologies", presented how constrained IoT devices can be used with the blockchain technology. This is a joint work by N. Fotiou, V. A. Siris, and G.C. Polyzos from MMLab, funded by the SOFIE project. The paper is published in Lecture Notes in Computer Science, vol. 11342, pp. 443-452.

You can find more details in our paper in this link.

Business idea award

22-11-2018
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MMlab PhD candidate Andreas Papidas, with his One Connect team, won the 3rd prize in the 8th AUEB Innovation and Entrepreneurship contest

The team made a proposal, mockup and business plan regarding automatic bicycle accident warning and tracking using LoRaWAN IoT technologies.

Talk by Christos Bampis

15-10-2018
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Christos Bampis, who is currently a phd student at at the University of Texas at Austin, will give a talk on user quality of experience in video streaming applications

Talk abstract: Large-scale video streaming on demand has become possible thanks to numerous engineering achievements in fields such as video compression, high-speed computation and display technologies. Nevertheless, the skyrocketing needs for bandwidth and network resources consumed by video applications challenges modern video content delivery. Since the available bandwidth resources are limited, streaming service providers have to mediate between operation costs, bandwidth efficiency and maximizing user quality of experience. However, these goals are inherently conflicting and require knowledge of how user quality of experience is affected by the network-induced changes in video quality. Being able to understand and predict user quality of experience and perceptually optimize rate allocation, can have significant effects in better network utilization, reduced costs for service providers and improved user satisfaction. In this talk, we will discuss on subjective and objective approaches to study and predict user quality of experience in video streaming applications, by exploiting perceptual video quality and human behavioral responses to streaming-related video impairments.

Presenter's biography: Christos Bampis graduated from the ECE school at the National Technical University of Athens in 2014. He then received a PhD in Electrical Engineering from the University of Texas at Austin in 2018. His research interests span various research areas in image and video quality, quality of experience, image processing and computer vision. He recently started working as a software engineer at the Video Algorithms team at Netflix, focusing on perceptual video quality and quality of experience prediction algorithms.

Talk by Xenofon Vasilakos

08-10-2018
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Xenofon Vasilakos, who is currently postdoctoral fellow at Eurecom graduate school and research centera, France, will give a talk on "Cognitive Network and Slice Management in Virtualized Multi-Tenant 5G Networks" on Tuesday, October 9th, at room 414 of the Trias Str. building

Talk abstract: Fifth Generation (5G) mobile networks pose a major paradigm shift, aimed to improve efficiency and flexibility with a service-oriented architecture that delivers networks as-a-service. The underlying concept is to support multiple services and virtual networks over one or more physical network infrastructure providers, with respect to (wrt) different service definition and agreement requirements, control and management, and performance. This service-oriented 5G vision can address the vast variety of emerging resource-hungry wireless services due to the unprecedented proliferation of smartphone and Internet-of-Things (IoT) devices, via a network composition and resource sharing model that reduces both Capital Expenditure (CAPEX) and operating expenses (OPEX). The later is done by decoupling infrastructure providers (e.g., operators and data center owners), service providers (e.g., operators and verticals) and network function providers (e.g., vendors). Therefore, a 5G service can be built by combining multi-vendor physical network functions and Virtual Network Functions (VNFs), bringing network slicing to the foreground as a key enabler for the envisioned service-oriented 5G. Within this 5G context, a key concept for customizing and offering a slice in a flexible way is to automate its life-cycle management. Following a long period of remaining in obscurity, Machine Learning (ML)-based approaches have created a trend towards this direction in the literature due to breakthroughs made on computational devices (CPUs, GPUs and Tensor Processing Units (TPUs)), which qualify ML as an appropriate option. Nevertheless, Cognitive Network & Slice Management based on ML poses a series of challenges, spanning from the design process of the ML models up to their deployment and their runtime life-cycle, including their cooperation. In addition, another key challenge towards a 5G era is the ever-increasing demand for resource-hungry, content-rich services such as HD video streaming and augmented reality, which require both low latency and high reliability.
This talk will focus on three points of research within the context of Cognitive Network & Slice Management in virtualized multi-tenant 5G networks:
(a) A novel Methodology approach to Cognitive Network & Slice Management based on Machine Learning (ML) models for managing network and slice resources in a way that complies with slice Service Level Agreements (SLAs) and maximizes the revenue of the underlying physical network operator(s). The proposed methodology approach standardizes, orchestrates and automates all the necessary steps and actions for building and deploying efficient ML models as collaborative components of an integrated Cognitive Network & Slice Management system.
(b) LL-MEC, the first open-source Low-Latency Multi-access Edge Computing (MEC) platform enabling coordinated resource programmability in end-to-end slicing scenarios, mobile network monitoring, control, and programmability while retaining compatibility with 3GPP and ETSI specifications.
(c) Ongoing work on coordinated, multi-type resource allocation for E2E slicing.

Presenter's biography: Xenofon Vasilakos is a postdoctoral fellow at Eurecom graduate school and research center, the Communication Systems department. He is funded by the “Investments for the Future” LABEX scholarship programme. Currently, he is working on 5G slicing technologies with a particular focus on Multi-access Edge Computing solutions and cognition approaches inspired by Machine Learning models towards self-managed 5G mobile networks. He has acquired a Ph.D. in Informatics from the Athens University of Economics and Business (AUEB) by working on Information-Centric Networking architectures, protocols and distributed solutions for the Future Internet, with an emphasis on rendezvous networks and seamless mobility support. Before that, he obtained his M.Sc. degree in Parallel and Distributed Computer Systems in 2009 from the Vrije Universiteit Amsterdam and his B.Sc. in Informatics from AUEB in 2007. He has participated in EU funded H2020 ICT projects such as H2020-POINT and, currently, 5GPPP SliceNet and 5GPPP 5G-PICTURE. In the past, he has participated in the EU funded FP7 projects PSIRP and PURSUIT, as well as in the Greek government-funded project I-CAN on clean-slate Information-Centric Networking architectures.

Ph.D. defense by Yiannis Thomas

19-07-2018
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Yiannis Thomas successfully presented his Ph.D. thesis, with title "Multipath Internet Transport", on Wednesday July 18th

Thesis abstract: The proliferation of smartphones, with their multiple interfaces, and data servers, with their high-performance interconnection networks, has revived interest in multipath transport protocols. Multipath-TCP (MPTCP), the multipath extension of TCP, is currently available in the Apple iOS and Linux operating systems, enabling bandwidth aggregation, load balancing, and resilience to failures and disconnections due to mobility. However, the deployment of multipath transport is challenged by the address-based TCP/IP communication, which does not facilitate the seamless establishment of multiple paths among two end-points, and by the distributed hop-by-hop TCP/IP routing, which does not ensure the disjointness of the paths. Even when multiple paths are deployed, the use of many subflows is both a blessing and a curse for multipath TCP/IP protocols, as they tend to grasp an unfair share of bandwidth, thus becoming unfriendly to single-path TCP flows. The latest congestion control algorithms for MPTCP attempt to equalize the cumulative subflow throughput with the throughput of the fastest single-path flow in the same link, thus exchanging performance for TCP-friendliness. While TCP-friendly in the long run, these approaches exhibit high throughput convergence latency, thus being effective only for long-lived flows.
Our contribution to multipath transport is twofold. First, we introduce the multipath multisource Transport Protocol (mmTP), a transport-layer protocol that offers reliable multipath and multisource content delivery in the Publish-Subscribe Internet (PSI) architecture. mmTP increases the utilization of network processing resources, exploits on-path and off-path caching and does not require additional state at routers, or complex signaling during connection establishment. Second, we propose a novel hybrid multipath congestion control algorithm that enhances resource utilization through greedy friendliness, a design that meets the TCP-friendliness constraint only when is needed. The hybrid congestion control scheme consists of the novel end-to-end Normalized Multiflow Congestion Control (NMCC) algorithm, which offers instant convergence to TCP-Friendliness, and an in-network topology management module, that provides disjoint paths when possible and notifies end-users about shared bottlenecks otherwise. We finally discuss the integration of the proposed designs with the TCP/IP architecture: mmTP through Software Defined Networking (SDN) and NMCC through MPTCP.

Talk by Nikos Vasilakis

25-06-2018
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Nikos Vasilaki who is currently Ph.D. candidate in Computer and Information Science at the University of Pennsylvania, will give a talk on "Retrofitting Security in Applications with Many Third-party Modules" on Tuesday, June 26th, on the 6th floor (606 room) of the Evelpidon Str. building (graduate program building) of the Athens University of Economics and Business (AUEB)

Talk abstract: Developers of large-scale software systems use third-party modules to reduce costs and accelerate release cycles, at a risk to safety and security. I will introduce a set of techniques that exploit module boundaries to automate compartmentalization of systems and enforce security policies, enhancing reliability and security. Our system, BreakApp, transparently spawns modules in protected compartments while preserving their original behavior. Optional high-level policies decouple security assumptions made during development from requirements imposed for module composition and use. These policies allow fine-tuning trade-offs such as security and performance based on changing threat models or load patterns. Evaluation of BreakApp with a prototype implementation for JavaScript -- an environment that is notorioustoday for its high-impact security problems -- demonstrates feasibility by enabling simplified security hardening of existing systems with low performance overhead.

Presenter's biography: Nikos Vasilakis is a Ph.D. candidate in Computer and Information Science at the University of Pennsylvania. Broadly construed, his research focus is large-scale distributed systems, with branches into systems security and programming languages. In the past, he worked as a software engineer in industrial environments that blend engineering with a tablespoon of research (e.g., VMware).

BeSMART project completed

20-04-2018
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The BeSMART project has been successfully completed. MMLab members presented its outcome during the final review, which took place in Athens.
For more information about the BeSMART project, visit the project's page.

Talk by Michalis Faloutsos

02-04-2018
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Michalis Faloutsos who is currently a faculty member at the Computer Science Dpt and Director of Entrepreneurship in the University of California Riverside, will give a talk on "Can we reduce the first-mover-advantage of cyber-hackers?" on Tuesday, April 4th, on the 6th floor (606 room) of the Evelpidon Str. building (graduate program building) of the Athens University of Economics and Business (AUEB)

Talk abstract: Can we do better than just waiting for the next attack to happen? We aruge that security should become more proactive in order to minimize the damage that an attack, such as a DDoS or a virus, can have. This is a very ambitious goal, but we believe that we are making significant first steps towards it. Specifically, our work focuses on the following questions: a) Can we improve network security by mining social media? b)Can we analyze malware to detect artifacts that can help us block or even eliminate them? We present our efforts that attempt to address the above questions. First, we develop a systematic approach to extract actionable information from social media, focusing on security forums. Specifically, we develop RIPEx, a hands-free method to extract IP addresses, that are reported as malicious in the forums. The results are very encouraging: a handful of such forums can provide 4 times more malicious IP addresses compared to the well-known VirusTotal repository. Second, we present the value of the information that we can extract by analyzing malware binaries that target routers and IoT devices. To automate the study of such malware, we develop, RARE, a systematic and comprehensive system to extract patterns and communication artifacts that can help detect and contain malware, and also point us to the communication and control points of botnets.

Presenter's biography: Michalis Faloutsos is a faculty member at the Computer Science Dpt and Director of Entrepreneurship in the University of California Riverside. He got his bachelor's degree at the National Technical University of Athens and his M.Sc. and Ph.D. at the University of Toronto. His interests include, network and systems security, online social networks analytics, and network measurements. With his two brothers, he co-authored the paper "On powerlaws of the Internet topology" (SIGCOMM'99), which received the "Test of Time" award from ACM SIGCOMM. His research has resulted in more than 18K citations, an h-index greater than 56, and an i10-index greater than 120. His work has been supported by many NSF, DHS, ARL, and DAPRA grants, for a cumulative amount of more than $12M. He is the co-founder of stopthehacker.com, a web-security start-up, which got acquired by Cloudflare in November 2013. In Aug 2014, he co-founded programize.com, which provides product development as a service and grew to 55 people by its third year.

Talk by Salil Kanhere

21-03-2018
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Salil Kanhere who is currently an Associate Professor in the School of Computer Science and Engineering at UNSW Sydney, Australia, will give a talk on "A Lightweight Scalable Blockchain for Internet of Things" on Tuesday, March 22nd, on the 6th floor (606 room) of the Evelpidon Str. building (graduate program building) of the Athens University of Economics and Business (AUEB)

Talk abstract: BlockChain (BC) has attracted tremendous attention due to its immutable nature and the associated security and privacy benefits. In this talk, we argue that BC has the potential to overcome security and privacy challenges of Internet of Things (IoT). However, traditional instantiations of BC are computationally expensive, have limited scalability and incur significant bandwidth overheads and delays which are not suited to the IoT context. We propose a tiered Lightweight Scalable BC (LSB) that is optimized for IoT requirements. We explore LSB in a smart home setting as a representative example for broader IoT applications. Low resource devices in a smart home benefit from a centralized manager that establishes shared keys for communication and processes all incoming and outgoing requests. LSB achieves decentralization by forming an overlay network where high resource devices jointly manage a public BC that ensures end-to-end privacy and security. The overlay is organized as distinct clusters to reduce overheads and the cluster heads are responsible for managing the public BC. LSB incorporates several optimizations which include algorithms for lightweight consensus, distributed trust and throughput management. Qualitative arguments demonstrate that LSB is resilient to several security attacks. Extensive simulations show that LSB decreases packet overhead and delay and increases BC scalability compared to relevant baselines.

Presenter's biography: Salil Kanhere is an Associate Professor in the School of Computer Science and Engineering at UNSW Sydney, Australia. His research interests include Internet of Things, blockchain, pervasive and mobile computing, crowdsourcing, privacy and security. He has published 175 peer-reviewed articles and delivered over 20 keynote talks and technical tutorials on these topics. Salil regularly serves on the organizing committee of a number of IEEE and ACM international conferences. He currently serves as the Area Editor for Pervasive and Mobile Computing and Computer Communications. Salil is a Senior Member of both the IEEE and the ACM. He is a recipient of the Humboldt Research Fellowship.

UMObile project presentation

05-03-2018
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Christos-Alexandros Sarros, Ph.D student at the Democritus University of Thrace, Greece, and Vassilis Tsaoussidis, professor at the Democritus University of Thrace, Greece and adjunct professor at Athena RC, will give a talk on "A Universal, Mobile-Centric and Opportunistic Communications Architecture" on Tuesday, March 6th, on the 6th floor (606 room) of the Evelpidon Str. building (graduate program building) of the Athens University of Economics and Business (AUEB)

Talk abstract: The Future Internet architecture is expected to incorporate disruptive environments, new applications and information-centric services. Unlike the traditional host-centric access paradigm, where access to a desired content is mapped to its location, UMOBILE architecture relies on the information-centric communication model to enable the association of access to a desired content with the content itself and on the DTN technology to meet the requirements of opportunistic communications; the two approaches are integrated into a single architecture. Furthermore, our approach to push services near the edge of the network but also to interpret connectivity as a time-tolerant aspect, allows for the development of innovative applications that access data independent of the level of end-to-end connectivity availability. In this talk, we will highlight the design features of the UMOBILE architecture. Prior to that, a brief introduction to our group activities and relevant recent project results will be presented.

Presenters' biography: Christos-Alexandros Sarros obtained his diploma in electrical and computer engineering from Democritus University of Thrace, Greece, in 2016. Currently, he is pursuing a Ph.D. at the same university under the supervision of Prof. Vassilis Tsaoussidis, and is working as research assistant at the Athena Research and Innovation Center. His research interests lie in the area of information-centric networking and delay-/disruption-tolerant networking.
Vassilis Tsaoussidis is a professor at DUTH and adjunct professor at Athena RC, holding degrees in applied mathematics (Aristotle University) and computer science (Ph.D. in computer science, Humboldt University, Berlin). He joined the research community of Rutgers in 1996 and later the faculty communities of Stony Brook and Northeastern. He also joined MIT as a visiting professor in 2009. He was scientific leader for ESA, FP-7, and HORIZON 2020 projects, including the UMOBILE project. Vassilis was an active member of the Democritus University Board and had a vital role in redefining ethics in University administration.

SOFIE kickoff

26-01-2018
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On January 23-25, SOFIE's project kickoff meeting took place

MMLab members participated in the SOFIE project's kick-off meeting which took place on Janaury 23-25 in Athens, Greece. The meeting was hosted by Optimum SA. MMLab will be in charge of the evaluation of the SOFIE's platfrom and it will actively participate in all project's activities
For more information about the SOFIE project, visit the project's page

Achilles Project second review

19-01-2018
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Achilles Project second review took place on Januray 19, in Valencia, Spain

Achilles' team presented the project's initial results on January 19, Valencia, Spain. The review took place at the Universitat Politechica de Valencia, and the team demonstrated how Achilles can be used to provide access control for the Inter-IoT gateway.
For more information about Achilles visit the project's page

Talk by Vasilis Kemerlis

08-01-2018
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Vasilis Kemerlis who is currently assistant professor of Computer Science at Brown University, will give a talk on "Secure Operating Systems" on Tuesday, January 9, on the 6th floor (606 room) of the Evelpidon Str. building (graduate program building) of the Athens University of Economics and Business (AUEB)

Talk abstract: Modern operating systems consist of large, monolithic blobs of complex code, and are plagued with vulnerabilities that allow perpetrators to exploit them for profit. This, coupled with the sophistication of modern adversaries, makes the need for effective and targeted defenses more critical than ever. In this talk, I will present our work on developing novel protection mechanisms and exploit prevention techniques that improve the security posture of commodity operating system kernels. In particular, I will discuss kR^X and XPFO, two projects whose goal is to harden contemporary OSes, against attacks that exploit memory safety vulnerabilities in kernel code, without entailing super-privileged software (e.g., a hypervisor or VMM). In addition, I will talk about ret2dir, a new kernel exploitation technique that we developed, which unveils how standard OS design approaches can significantly weaken the effectiveness of deployed, state of-the-art kernel defenses.

Presenter's biography: Vasileios (Vasilis) Kemerlis is an Assistant Professor of Computer Science at Brown University. His research interests are in the areas of systems and software security, with a focus on OS kernel protection, automated software hardening, and information-flow tracking. His work on kernel security has been profiled by press and social media outlets, including LWN.net, the Linux Journal, Dark Reading, and Hacker News, won the first prize in the Applied Security Research Paper competition, at the Cyber Security Awareness Week (CSAW) 2014, and led to the adoption of kernel hardening techniques from OpenBSD and Qualcomm's MSM Android. In addition, Vasilis has contributed to the design and implementation of Microsoft's primary solution for automatically triaging crash dumps, which is now part of the Windows Error Reporting Platform. In the past, he was a member of the Solaris Core Kernel team at Oracle, where he worked on adding support for full Address Space Layout Randomization (ASLR) in the Solaris OS. Lastly, Vasilis has co-invented the first cache-based side channel attack that can be entirely executed from JavaScript context, which resulted in Apple and Mozilla limiting the time resolution of JavaScript's performance API (as a mitigation to the proposed attack), and the Tor Project decreasing the time precision of JavaScript entirely. Vasilis holds a PhD (2015), MPhil (2013), and MS (2010) in Computer Science from Columbia University, and a BS (2006) in Computer Science from Athens University of Economics and Business.

Workshop on blockhain technologies

19-12-2017
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On of December 1, 2017 we had our first internal workshop on blockchain technologies. The goal of the workshop was to introduce blockhains and smart contracts and to discuss their applications in the domain of the Internet of Things.

Program and presentations
The agenda of the workshop follows:

Talk by Stratis Ioannidis

18-12-2017
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Stratis Ioannidis who is currently assistant professor in the Electrical and Computer Engineering Department of Northeastern University, in Boston, MA will give a talk on "Adaptive Caching Networks with Optimality Guarantees" on Tuesday, December 19st, on the 6th floor (606 room) of the Evelpidon Str. building (graduate program building) of the Athens University of Economics and Business (AUEB)

Talk abstract: Optimally placing content over a network of arises in many networking applications. Given the content demand, described by content requests and paths they follow, we wish to determine the content placement that maximizes the expected caching gain, i.e., the reduction of routing costs due to intermediate caching. The offline version of this problem is NP-hard. To make matters worse, in most cases, both the demand and the network topology may be a priori unknown; hence, distributed, adaptive content placement algorithms that yield constant approximation guarantees are desired. We show that path replication, an algorithm encountered often in both networking literature and in practice, can be arbitrarily suboptimal when combined with traditional cache eviction policies, like LRU, LFU, or FIFO. We propose a distributed, adaptive algorithm that provably constructs a probabilistic content placement within 1−1/e factor from the optimal, in expectation. Finally, we extend these results to optimizing caching and routing decisions jointly.

Presenter's biography: Stratis Ioannidis is an assistant professor in the Electrical and Computer Engineering Department of Northeastern University, in Boston, MA, where he also holds a courtesy appointment with the College of Computer and Information Science. He received his B.Sc. (2002) in Electrical and Computer Engineering from the National Technical University of Athens, Greece, and his M.Sc. (2004) and Ph.D. (2009) in Computer Science from the University of Toronto, Canada. Prior to joining Northeastern, he was a research scientist at the Technicolor research centers in Paris, France, and Palo Alto, CA, as well as at Yahoo Labs in Sunnyvale, CA. He is the recipient of a Google Faculty Research Award and a best paper award at ICN 2017