@inproceedings{4411,
abstract = {While a lot of research in distributed computing has covered solutions for self-stabilizing computing and topologies, there is far less work on self-stabilization for distributed data structures.
Considering crashing peers in peer-to-peer networks, it should not be taken for granted that a distributed data structure remains intact.
In this work, we present a self-stabilizing protocol for a distributed data structure called the hashed Patricia Trie (Kniesburges and Scheideler WALCOM'11) that enables efficient prefix search on a set of keys.
The data structure has a wide area of applications including string matching problems while offering low overhead and efficient operations when embedded on top of a distributed hash table.
Especially, longest prefix matching for $x$ can be done in $\mathcal{O}(\log |x|)$ hash table read accesses.
We show how to maintain the structure in a self-stabilizing way.
Our protocol assures low overhead in a legal state and a total (asymptotically optimal) memory demand of $\Theta(d)$ bits, where $d$ is the number of bits needed for storing all keys.},
author = {Knollmann, Till and Scheideler, Christian},
booktitle = {Proceedings of the 20th International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS)},
editor = {Izumi, Taisuke and Kuznetsov, Petr},
keyword = {Self-Stabilizing, Prefix Search, Distributed Data Structure},
location = {Tokyo},
publisher = {Springer, Cham},
title = {{A Self-Stabilizing Hashed Patricia Trie}},
doi = {10.1007/978-3-030-03232-6_1},
volume = {11201},
year = {2018},
}
@techreport{5820,
abstract = {In this paper, we investigate the use of trusted execution environments (TEEs, such as Intel's SGX) for an anonymous communication infrastructure over untrusted networks.
For this, we present the general idea of exploiting trusted execution environments for the purpose of anonymous communication, including a continuous-time security framework that models strong anonymity guarantees in the presence of an adversary that observes all network traffic and can adaptively corrupt a constant fraction of participating nodes.
In our framework, a participating node can generate a number of unlinkable pseudonyms. Messages are sent from and to pseudonyms, allowing both senders and receivers of messages to remain anonymous. We introduce a concrete construction, which shows viability of our TEE-based approach to anonymous communication. The construction draws from techniques from cryptography and overlay networks.
Our techniques are very general and can be used as a basis for future constructions with similar goals.},
author = {Blömer, Johannes and Bobolz, Jan and Scheideler, Christian and Setzer, Alexander},
title = {{Provably Anonymous Communication Based on Trusted Execution Environments}},
year = {2018},
}
@article{5984,
author = {Scheideler, Christian},
journal = {Theor. Comput. Sci.},
pages = {1},
title = {{Preface}},
doi = {10.1016/j.tcs.2018.11.004},
volume = {751},
year = {2018},
}
@inproceedings{4563,
abstract = {Routing is a challenging problem for wireless ad hoc networks, especially when the nodes are mobile and spread so widely that in most cases multiple hops are needed to route a message from one node to another. In fact, it is known that any online routing protocol has a poor performance in the worst case, in a sense that there is a distribution of nodes resulting in bad routing paths for that protocol, even if the nodes know their geographic positions and the geographic position of the destination of a message is known. The reason for that is that radio holes in the ad hoc network may require messages to take long detours in order to get to a destination, which are hard to find in an online fashion.
In this paper, we assume that the wireless ad hoc network can make limited use of long-range links provided by a global communication infrastructure like a cellular infrastructure or a satellite in order to compute an abstraction of the wireless ad hoc network that allows the messages to be sent along near-shortest paths in the ad hoc network. We present distributed algorithms that compute an abstraction of the ad hoc network in $\mathcal{O}\left(\log ^2 n\right)$ time using long-range links, which results in $c$-competitive routing paths between any two nodes of the ad hoc network for some constant $c$ if the convex hulls of the radio holes do not intersect. We also show that the storage needed for the abstraction just depends on the number and size of the radio holes in the wireless ad hoc network and is independent on the total number of nodes, and this information just has to be known to a few nodes for the routing to work.
},
author = {Jung, Daniel and Kolb, Christina and Scheideler, Christian and Sundermeier, Jannik},
booktitle = {Proceedings of the 14th International Symposium on Algorithms and Experiments for Wireless Networks (ALGOSENSORS) },
keyword = {greedy routing, ad hoc networks, convex hulls, c-competitiveness},
location = {Helsinki},
publisher = {Springer},
title = {{Competitive Routing in Hybrid Communication Networks}},
year = {2018},
}
@inproceedings{105,
abstract = {We initiate the study of network monitoring algorithms in a class of hybrid networks in which the nodes are connected by an external network and an internal network (as a short form for externally and internally controlled network). While the external network lies outside of the control of the nodes (or in our case, the monitoring protocol running in them) and might be exposed to continuous changes, the internal network is fully under the control of the nodes. As an example, consider a group of users with mobile devices having access to the cell phone infrastructure. While the network formed by the WiFi connections of the devices is an external network (as its structure is not necessarily under the control of the monitoring protocol), the connections between the devices via the cell phone infrastructure represent an internal network (as it can be controlled by the monitoring protocol). Our goal is to continuously monitor properties of the external network with the help of the internal network. We present scalable distributed algorithms that efficiently monitor the number of edges, the average node degree, the clustering coefficient, the bipartiteness, and the weight of a minimum spanning tree. Their performance bounds demonstrate that monitoring the external network state with the help of an internal network can be done much more efficiently than just using the external network, as is usually done in the literature.},
author = {Gmyr, Robert and Hinnenthal, Kristian and Scheideler, Christian and Sohler, Christian},
booktitle = {Proceedings of the 44th International Colloquium on Automata, Languages, and Programming (ICALP)},
pages = {137:1----137:15},
title = {{Distributed Monitoring of Network Properties: The Power of Hybrid Networks}},
doi = {10.4230/LIPIcs.ICALP.2017.137},
year = {2017},
}
@article{1813,
author = {P. Fekete, Sandor and W. Richa, Andrea and Römer, Kay and Scheideler, Christian},
journal = {SIGACT News},
number = {2},
pages = {87----94},
title = {{Algorithmic Foundations of Programmable Matter Dagstuhl Seminar 16271}},
doi = {10.1145/3106700.3106713},
year = {2017},
}
@article{3872,
abstract = {This paper considers the problem of how to efficiently share a wireless medium which is subject to harsh external interference or even jamming. So far, this problem is understood only in simplistic single-hop or unit disk graph models. We in this paper initiate the study of MAC protocols for the SINR interference model (a.k.a. physical model). This paper makes two contributions. First, we introduce a new adversarial SINR model which captures a wide range of interference phenomena. Concretely, we consider a powerful, adaptive adversary which can jam nodes at arbitrary times and which is only limited by some energy budget. Our second contribution is a distributed MAC protocol called Sade which provably achieves a constant competitive throughput in this environment: we show that, with high probability, the protocol ensures that a constant fraction of the non-blocked time periods is used for successful transmissions.},
author = {Ogierman, Adrian and Richa, Andrea and Scheideler, Christian and Schmid, Stefan and Zhang, Jin},
issn = {0178-2770},
journal = {Distributed Computing},
number = {3},
pages = {241--254},
publisher = {Springer Nature},
title = {{Sade: competitive MAC under adversarial SINR}},
doi = {10.1007/s00446-017-0307-1},
volume = {31},
year = {2017},
}
@inproceedings{125,
abstract = {Searching for other participants is one of the most important operations in a distributed system.We are interested in topologies in which it is possible to route a packet in a fixed number of hops until it arrives at its destination.Given a constant $d$, this paper introduces a new self-stabilizing protocol for the $q$-ary $d$-dimensional de Bruijn graph ($q = \sqrt[d]{n}$) that is able to route any search request in at most $d$ hops w.h.p., while significantly lowering the node degree compared to the clique: We require nodes to have a degree of $\mathcal O(\sqrt[d]{n})$, which is asymptotically optimal for a fixed diameter $d$.The protocol keeps the expected amount of edge redirections per node in $\mathcal O(\sqrt[d]{n})$, when the number of nodes in the system increases by factor $2^d$.The number of messages that are periodically sent out by nodes is constant.},
author = {Feldmann, Michael and Scheideler, Christian},
booktitle = {Proceedings of the 19th International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS)},
isbn = {978-3-319-69083-4},
pages = {250--264 },
publisher = {Springer, Cham},
title = {{A Self-Stabilizing General De Bruijn Graph}},
doi = {10.1007/978-3-319-69084-1_17},
volume = {10616},
year = {2017},
}
@article{1814,
author = {Derakhshandeh, Zahra and Gmyr, Robert and W. Richa, Andrea and Scheideler, Christian and Strothmann, Thim Frederik},
journal = {Theor. Comput. Sci.},
pages = {56----68},
title = {{Universal coating for programmable matter}},
doi = {10.1016/j.tcs.2016.02.039},
year = {2017},
}
@inproceedings{1815,
author = {J. Daymude, Joshua and Gmyr, Robert and W. Richa, Andrea and Scheideler, Christian and Strothmann, Thim Frederik},
booktitle = {Algorithms for Sensor Systems - 13th International Symposium on Algorithms and Experiments for Wireless Sensor Networks, ALGOSENSORS 2017, Vienna, Austria, September 7-8, 2017, Revised Selected Papers},
pages = {127----140},
title = {{Improved Leader Election for Self-organizing Programmable Matter}},
doi = {10.1007/978-3-319-72751-6_10},
year = {2017},
}
@article{1812,
author = {Koutsopoulos, Andreas and Scheideler, Christian and Strothmann, Thim Frederik},
journal = {Inf. Comput.},
pages = {408----424},
title = {{Towards a universal approach for the finite departure problem in overlay networks}},
doi = {10.1016/j.ic.2016.12.006},
year = {2017},
}
@inproceedings{155,
abstract = {We present a self-stabilizing algorithm for overlay networks that, for an arbitrary metric given by a distance oracle, constructs the graph representing that metric. The graph representing a metric is the unique minimal undirected graph such that for any pair of nodes the length of a shortest path between the nodes corresponds to the distance between the nodes according to the metric. The algorithm works under both an asynchronous and a synchronous daemon. In the synchronous case, the algorithm stablizes in time O(n) and it is almost silent in that after stabilization a node sends and receives a constant number of messages per round.},
author = {Gmyr, Robert and Lefèvre, Jonas and Scheideler, Christian},
booktitle = {Proceedings of the 18th International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS)},
pages = {248----262},
title = {{Self-stabilizing Metric Graphs}},
doi = {10.1007/978-3-319-49259-9_20},
year = {2016},
}
@inproceedings{1837,
author = {Derakhshandeh, Zahra and Gmyr, Robert and W. Richa, Andrea and Scheideler, Christian and Strothmann, Thim Frederik},
booktitle = {Proceedings of the 28th ACM Symposium on Parallelism in Algorithms and Architectures, SPAA 2016, Asilomar State Beach/Pacific Grove, CA, USA, July 11-13, 2016},
pages = {289----299},
publisher = {ACM},
title = {{Universal Shape Formation for Programmable Matter}},
doi = {10.1145/2935764.2935784},
year = {2016},
}
@inbook{1845,
author = {W. Richa, Andrea and Scheideler, Christian},
booktitle = {Encyclopedia of Algorithms},
pages = {999----1002},
title = {{Jamming-Resistant MAC Protocols for Wireless Networks}},
doi = {10.1007/978-1-4939-2864-4_593},
year = {2016},
}
@inproceedings{215,
abstract = {We present three robust overlay networks: First, we present a network that organizes the nodes into an expander and is resistant to even massive adversarial churn. Second, we develop a network based on the hypercube that maintains connectivity under adversarial DoS-attacks. For the DoS-attacks we use the notion of a Omega(log log n)-late adversary which only has access to topological information that is at least Omega(log log n) rounds old. Finally, we develop a network that combines both churn- and DoS-resistance. The networks gain their robustness through constant network reconfiguration, i.e., the topology of the networks changes constantly. Our reconguration algorithms are based on node sampling primitives for expanders and hypercubes that allow each node to sample a logarithmic number of nodes uniformly at random in O(log log n) communication rounds. These primitives are specific to overlay networks and their optimal runtime represents an exponential improvement over known techniques. Our results have a wide range of applications, for example in the area of scalable and robust peer-to-peer systems.},
author = {Drees, Maximilian and Gmyr, Robert and Scheideler, Christian},
booktitle = {Proceedings of the 28th ACM Symposium on Parallelism in Algorithms and Architectures (SPAA)},
pages = {417----427},
title = {{Churn- and DoS-resistant Overlay Networks Based on Network Reconfiguration}},
doi = {10.1145/2935764.2935783},
year = {2016},
}
@article{1835,
author = {Schmid, Stefan and Avin, Chen and Scheideler, Christian and Borokhovich, Michael and Haeupler, Bernhard and Lotker, Zvi},
journal = {IEEE/ACM Trans. Netw.},
number = {3},
pages = {1421----1433},
title = {{SplayNet: Towards Locally Self-Adjusting Networks}},
doi = {10.1109/TNET.2015.2410313},
year = {2016},
}
@inproceedings{142,
abstract = {For overlay networks, the ability to recover from a variety of problems like membership changes or faults is a key element to preserve their functionality. In recent years, various self-stabilizing overlay networks have been proposed that have the advantage of being able to recover from any illegal state. However, the vast majority of these networks cannot give any guarantees on its functionality while the recovery process is going on. We are especially interested in searchability, i.e., the functionality that search messages for a specific identifier are answered successfully if a node with that identifier exists in the network. We investigate overlay networks that are not only self-stabilizing but that also ensure that monotonic searchability is maintained while the recovery process is going on, as long as there are no corrupted messages in the system. More precisely, once a search message from node u to another node v is successfully delivered, all future search messages from u to v succeed as well. Monotonic searchability was recently introduced in OPODIS 2015, in which the authors provide a solution for a simple line topology.We present the first universal approach to maintain monotonic searchability that is applicable to a wide range of topologies. As the base for our approach, we introduce a set of primitives for manipulating overlay networks that allows us to maintain searchability and show how existing protocols can be transformed to use theses primitives.We complement this result with a generic search protocol that together with the use of our primitives guarantees monotonic searchability.As an additional feature, searching existing nodes with the generic search protocol is as fast as searching a node with any other fixed routing protocol once the topology has stabilized.},
author = {Scheideler, Christian and Setzer, Alexander and Strothmann, Thim Frederik},
booktitle = {Proceedings of the 30th International Symposium on Distributed Computing (DISC)},
pages = {71----84},
title = {{Towards a Universal Approach for Monotonic Searchability in Self-stabilizing Overlay Networks}},
doi = {10.1007/978-3-662-53426-7_6},
year = {2016},
}
@inproceedings{1836,
author = {Derakhshandeh, Zahra and Gmyr, Robert and Porter, Alexandra and W. Richa, Andrea and Scheideler, Christian and Strothmann, Thim Frederik},
booktitle = {DNA Computing and Molecular Programming - 22nd International Conference, DNA 22, Munich, Germany, September 4-8, 2016, Proceedings},
pages = {148----164},
title = {{On the Runtime of Universal Coating for Programmable Matter}},
doi = {10.1007/978-3-319-43994-5_10},
volume = {9818},
year = {2016},
}
@inproceedings{1851,
author = {Derakhshandeh, Zahra and Gmyr, Robert and W. Richa, Andrea and Scheideler, Christian and Strothmann, Thim Frederik},
booktitle = {Proceedings of the Second Annual International Conference on Nanoscale Computing and Communication, NANOCOM' 15, Boston, MA, USA, September 21-22, 2015},
isbn = {978-1-4503-3674-1},
pages = {21:1----21:2},
publisher = {ACM},
title = {{An Algorithmic Framework for Shape Formation Problems in Self-Organizing Particle Systems}},
doi = {10.1145/2800795.2800829},
year = {2015},
}
@article{327,
abstract = {We consider the problem of resource discovery in distributed systems. In particular we give an algorithm, such that each node in a network discovers the address of any other node in the network. We model the knowledge of the nodes as a virtual overlay network given by a directed graph such that complete knowledge of all nodes corresponds to a complete graph in the overlay network. Although there are several solutions for resource discovery, our solution is the first that achieves worst-case optimal work for each node, i.e. the number of addresses (O(n)O(n)) or bits (O(nlogn)O(nlogn)) a node receives or sends coincides with the lower bound, while ensuring only a linear runtime (O(n)O(n)) on the number of rounds.},
author = {Kniesburges, Sebastian and Koutsopoulos, Andreas and Scheideler, Christian},
journal = {Theoretical Computer Science},
pages = {67--79},
publisher = {Elsevier},
title = {{A deterministic worst-case message complexity optimal solution for resource discovery}},
doi = {10.1016/j.tcs.2014.11.027},
year = {2015},
}
@inproceedings{1852,
author = {Derakhshandeh, Zahra and Gmyr, Robert and Strothmann, Thim Frederik and A. Bazzi, Rida and W. Richa, Andrea and Scheideler, Christian},
booktitle = {Proceedings of the 2015 ACM Symposium on Principles of Distributed Computing, PODC 2015, Donostia-San Sebasti{\'{a}}n, Spain, July 21 - 23, 2015},
isbn = {978-1-4503-3617-8},
pages = {67----69},
publisher = {ACM},
title = {{Brief Announcement: On the Feasibility of Leader Election and Shape Formation with Self-Organizing Programmable Matter}},
doi = {10.1145/2767386.2767451},
year = {2015},
}
@inproceedings{241,
abstract = {Distributed applications are commonly based on overlay networks interconnecting their sites so that they can exchange information. For these overlay networks to preserve their functionality, they should be able to recover from various problems like membership changes or faults. Various self-stabilizing overlay networks have already been proposed in recent years, which have the advantage of being able to recover from any illegal state, but none of these networks can give any guarantees on its functionality while the recovery process is going on. We initiate research on overlay networks that are not only self-stabilizing but that also ensure that searchability is maintained while the recovery process is going on, as long as there are no corrupted messages in the system. More precisely, once a search message from node u to another node v is successfully delivered, all future search messages from u to v succeed as well. We call this property monotonic searchability. We show that in general it is impossible to provide monotonic searchability if corrupted messages are present in the system, which justifies the restriction to system states without corrupted messages. Furthermore, we provide a self-stabilizing protocol for the line for which we can also show monotonic searchability. It turns out that even for the line it is non-trivial to achieve this property. Additionally, we extend our protocol to deal with node departures in terms of the Finite Departure Problem of Foreback et. al (SSS 2014). This makes our protocol even capable of handling node dynamics.},
author = {Scheideler, Christian and Setzer, Alexander and Strothmann, Thim Frederik},
booktitle = {Proceedings of the 19th International Conference on Principles of Distributed Systems (OPODIS)},
title = {{Towards Establishing Monotonic Searchability in Self-Stabilizing Data Structures}},
doi = {10.4230/LIPIcs.OPODIS.2015.24},
year = {2015},
}
@article{284,
abstract = {In this work, we present the first scalable distributed information system, that is, a system with low storage overhead, that is provably robust against denial-of-service (DoS) attacks by a current insider. We allow a current insider to have complete knowledge about the information system and to have the power to block any ϵ-fraction of its servers by a DoS attack, where ϵ can be chosen up to a constant. The task of the system is to serve any collection of lookup requests with at most one per nonblocked server in an efficient way despite this attack. Previously, scalable solutions were only known for DoS attacks of past insiders, where a past insider only has complete knowledge about some past time point t0 of the information system. Scheideler et al. [Awerbuch and Scheideler 2007; Baumgart et al. 2009] showed that in this case, it is possible to design an information system so that any information that was inserted or last updated after t0 is safe against a DoS attack. But their constructions would not work at all for a current insider. The key idea behind our IRIS system is to make extensive use of coding. More precisely, we present two alternative distributed coding strategies with an at most logarithmic storage overhead that can handle up to a constant fraction of blocked servers.},
author = {Eikel, Martina and Scheideler, Christian},
journal = {Transactions on Parallel Computing},
number = {3},
pages = {18:1----18:33},
publisher = {ACM},
title = {{IRIS: A Robust Information System Against Insider DoS Attacks}},
doi = {10.1145/2809806},
year = {2015},
}
@inproceedings{1853,
author = {Koutsopoulos, Andreas and Scheideler, Christian and Strothmann, Thim Frederik},
booktitle = {Proceedings of the 27th ACM on Symposium on Parallelism in Algorithms and Architectures, SPAA 2015, Portland, OR, USA, June 13-15, 2015},
isbn = {978-1-4503-3588-1},
pages = {77----79},
publisher = {ACM},
title = {{Brief Announcement: Towards a Universal Approach for the Finite Departure Problem in Overlay Networks}},
doi = {10.1145/2755573.2755614},
year = {2015},
}
@inproceedings{242,
abstract = {A fundamental problem for overlay networks is to safely exclude leaving nodes, i.e., the nodes requesting to leave the overlay network are excluded from it without affecting its connectivity. There are a number of studies for safe node exclusion if the overlay is in a well-defined state, but almost no formal results are known for the case in which the overlay network is in an arbitrary initial state, i.e., when looking for a self-stabilizing solution for excluding leaving nodes. We study this problem in two variants: the Finite Departure Problem (FDP) and the Finite Sleep Problem (FSP). In the FDP the leaving nodes have to irrevocably decide when it is safe to leave the network, whereas in the FSP, this leaving decision does not have to be final: the nodes may resume computation when woken up by an incoming message. We are the first to present a self-stabilizing protocol for the FDP and the FSP that can be combined with a large class of overlay maintenance protocols so that these are then guaranteed to safely exclude leaving nodes from the system from any initial state while operating as specified for the staying nodes. In order to formally define the properties these overlay maintenance protocols have to satisfy, we identify four basic primitives for manipulating edges in an overlay network that might be of independent interest.},
author = {Koutsopoulos, Andreas and Scheideler, Christian and Strothmann, Thim Frederik},
booktitle = {Proceedings of the 17th International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS)},
pages = {201--216},
title = {{Towards a Universal Approach for the Finite Departure Problem in Overlay Networks}},
doi = {10.1007/978-3-319-21741-3_14},
year = {2015},
}
@inproceedings{1850,
author = {Derakhshandeh, Zahra and Gmyr, Robert and Strothmann, Thim Frederik and A. Bazzi, Rida and W. Richa, Andrea and Scheideler, Christian},
booktitle = {DNA Computing and Molecular Programming - 21st International Conference, DNA 21, Boston and Cambridge, MA, USA, August 17-21, 2015. Proceedings},
isbn = {978-3-319-21998-1},
pages = {117----132},
title = {{Leader Election and Shape Formation with Self-organizing Programmable Matter}},
doi = {10.1007/978-3-319-21999-8_8},
volume = {9211},
year = {2015},
}
@inproceedings{1863,
author = {Derakhshandeh, Zahra and Dolev, Shlomi and Gmyr, Robert and W. Richa, Andrea and Scheideler, Christian and Strothmann, Thim Frederik},
booktitle = {26th ACM Symposium on Parallelism in Algorithms and Architectures, SPAA'14, Prague, Czech Republic - June 23 - 25, 2014},
isbn = {978-1-4503-2821-0},
pages = {220----222},
publisher = {ACM},
title = {{Brief announcement: amoebot - a new model for programmable matter}},
doi = {10.1145/2612669.2612712},
year = {2014},
}
@inproceedings{371,
abstract = {In this work we present the first distributed storage system that is provably robust against crash failures issued by an adaptive adversary, i.e., for each batch of requests the adversary can decide based on the entire system state which servers will be unavailable for that batch of requests. Despite up to \gamma n^{1/\log\log n} crashed servers, with \gamma>0 constant and n denoting the number of servers, our system can correctly process any batch of lookup and write requests (with at most a polylogarithmic number of requests issued at each non-crashed server) in at most a polylogarithmic number of communication rounds, with at most polylogarithmic time and work at each server and only a logarithmic storage overhead. Our system is based on previous work by Eikel and Scheideler (SPAA 2013), who presented IRIS, a distributed information system that is provably robust against the same kind of crash failures. However, IRIS is only able to serve lookup requests. Handling both lookup and write requests has turned out to require major changes in the design of IRIS.},
author = {Scheideler, Christian and Setzer, Alexander and Eikel, Martina},
booktitle = {Proceedings of the 18th International Conference on Principles of Distributed Systems (OPODIS)},
pages = {107----122},
title = {{RoBuSt: A Crash-Failure-Resistant Distributed Storage System}},
doi = {10.1007/978-3-319-14472-6_8},
year = {2014},
}
@inproceedings{446,
abstract = {This paper considers the problem of how to efficiently share a wireless medium which is subject to harsh external interference or even jamming. While this problem has already been studied intensively for simplistic single-hop or unit disk graph models, we make a leap forward and study MAC protocols for the SINR interference model (a.k.a. the physical model). We make two contributions. First, we introduce a new adversarial SINR model which captures a wide range of interference phenomena. Concretely, we consider a powerful, adaptive adversary which can jam nodes at arbitrary times and which is only limited by some energy budget. The second contribution of this paper is a distributed MAC protocol which provably achieves a constant competitive throughput in this environment: we show that, with high probability, the protocol ensures that a constant fraction of the non-blocked time periods is used for successful transmissions.},
author = {Ogierman, Adrian and Richa, Andrea W. and Scheideler, Christian and Schmid, Stefan and Zhang, Jin},
booktitle = {Proceedings of the 33rd Annual IEEE International Conference on Computer Communications (INFOCOM)},
pages = {2751----2759},
title = {{Competitive MAC under adversarial SINR}},
doi = {10.1109/INFOCOM.2014.6848224},
year = {2014},
}
@inproceedings{459,
abstract = {In this survey article, we discuss two algorithmic research areas that emerge from problems that arise when resources are offered in the cloud. The first area, online leasing, captures problems arising from the fact that resources in the cloud are not bought, but leased by cloud vendors. The second area, Distributed Storage Systems, deals with problems arising from so-called cloud federations, i.e., when several cloud providers are needed to fulfill a given task.},
author = {Kniesburges, Sebastian and Markarian, Christine and Meyer auf der Heide, Friedhelm and Scheideler, Christian},
booktitle = {Proceedings of the 21st International Colloquium on Structural Information and Communication Complexity (SIROCCO)},
pages = {1--13},
title = {{Algorithmic Aspects of Resource Management in the Cloud}},
doi = {10.1007/978-3-319-09620-9_1},
year = {2014},
}
@article{378,
abstract = {The Chord peer-to-peer system is considered, together with CAN, Tapestry and Pastry, as one of the pioneering works on peer-to-peer distributed hash tables (DHT) that inspired a large volume of papers and projects on DHTs as well as peer-to-peer systems in general. Chord, in particular, has been studied thoroughly, and many variants of Chord have been presented that optimize various criteria. Also, several implementations of Chord are available on various platforms. Though Chord is known to be very efficient and scalable and it can handle churn quite well, no protocol is known yet that guarantees that Chord is self-stabilizing, i.e., the Chord network can be recovered from any initial state in which the network is still weakly connected. This is not too surprising since it is known that the Chord network is not locally checkable for its current topology. We present a slight extension of the Chord network, called Re-Chord (reactive Chord), that turns out to be locally checkable, and we present a self-stabilizing distributed protocol for it that can recover the Re-Chord network from any initial state, in which the n peers are weakly connected, in O(nlogn) communication rounds. We also show that our protocol allows a new peer to join or an old peer to leave an already stable Re-Chord network so that within O(logn)^2) communication rounds the Re-Chord network is stable again.},
author = {Kniesburges, Sebastian and Koutsopoulos, Andreas and Scheideler, Christian},
journal = {Theory of Computing Systems},
number = {3},
pages = {591--612},
publisher = {Springer},
title = {{Re-Chord: A Self-stabilizing Chord Overlay Network}},
doi = {10.1007/s00224-012-9431-2},
year = {2014},
}
@inproceedings{397,
abstract = {We present a factor $14D^2$ approximation algorithm for the minimum linear arrangement problem on series-parallel graphs, where $D$ is the maximum degree in the graph. Given a suitable decomposition of the graph, our algorithm runs in time $O(|E|)$ and is very easy to implement. Its divide-and-conquer approach allows for an effective parallelization. Note that a suitable decomposition can also be computed in time $O(|E|\log{|E|})$ (or even $O(\log{|E|}\log^*{|E|})$ on an EREW PRAM using $O(|E|)$ processors). For the proof of the approximation ratio, we use a sophisticated charging method that uses techniques similar to amortized analysis in advanced data structures. On general graphs, the minimum linear arrangement problem is known to be NP-hard. To the best of our knowledge, the minimum linear arrangement problem on series-parallel graphs has not been studied before.},
author = {Scheideler, Christian and Eikel, Martina and Setzer, Alexander},
booktitle = {Proceedings of the 12th Workshop on Approximation and Online Algorithms (WAOA)},
pages = {168----180},
title = {{Minimum Linear Arrangement of Series-Parallel Graphs}},
year = {2014},
}
@inproceedings{412,
abstract = {In this paper we present and analyze HSkip+, a self-stabilizing overlay network for nodes with arbitrary heterogeneous bandwidths. HSkip+ has the same topology as the Skip+ graph proposed by Jacob et al. [PODC 2009] but its self-stabilization mechanism significantly outperforms the self-stabilization mechanism proposed for Skip+. Also, the nodes are now ordered according to their bandwidths and not according to their identifiers. Various other solutions have already been proposed for overlay networks with heterogeneous bandwidths, but they are not self-stabilizing. In addition to HSkip+ being self-stabilizing, its performance is on par with the best previous bounds on the time and work for joining or leaving a network of peers of logarithmic diameter and degree and arbitrary bandwidths. Also, the dilation and congestion for routing messages is on par with the best previous bounds for such networks, so that HSkip+ combines the advantages of both worlds. Our theoretical investigations are backed by simulations demonstrating that HSkip+ is indeed performing much better than Skip+ and working correctly under high churn rates.},
author = {Feldotto, Matthias and Scheideler, Christian and Graffi, Kalman},
booktitle = {Proceedings of the 14th IEEE International Conference on Peer-to-Peer Computing (P2P)},
pages = {1--10},
title = {{HSkip+: A Self-Stabilizing Overlay Network for Nodes with Heterogeneous Bandwidths}},
doi = {10.1109/P2P.2014.6934300},
year = {2014},
}
@article{1858,
author = {Jacob, Riko and W. Richa, Andrea and Scheideler, Christian and Schmid, Stefan and Täubig, Hanjo},
journal = {J. ACM},
number = {6},
pages = {36:1----36:26},
title = {{SKIP*: A Self-Stabilizing Skip Graph}},
doi = {10.1145/2629695},
year = {2014},
}
@inproceedings{393,
abstract = {A fundamental problem for peer-to-peer systems is to maintain connectivity while nodes are leaving, i.e., the nodes requesting to leave the peer-to-peer system are excluded from the overlay network without affecting its connectivity. There are a number of studies for safe node exclusion if the overlay is in a well-defined state initially. Surprisingly, the problem is not formally studied yet for the case in which the overlay network is in an arbitrary initial state, i.e., when looking for a self-stabilizing solution for excluding leaving nodes. We study this problem in two variants: the Finite Departure Problem (FDP) ) and the Finite Sleep Problem (FSP). In the FDP the leaving nodes have to irrevocably decide when it is safe to leave the network, whereas in the FSP, this leaving decision does not have to be final: the nodes may resume computation if necessary. We show that there is no self-stabilizing distributed algorithm for the FDP, even in a synchronous message passing model. To allow a solution, we introduce an oracle called NIDEC and show that it is sufficient even for the asynchronous message passing model by proposing an algorithm that can solve the FDP using NIDEC. We also show that a solution to the FSP does not require an oracle.},
author = {Foreback, Dianne and Koutsopoulos, Andreas and Nesterenko, Mikhail and Scheideler, Christian and Strothmann, Thim Frederik},
booktitle = {Proceedings of the 16th International Symposium on Stabilization, Safety, and Security of Distributed Systems},
pages = {48----62},
title = {{On Stabilizing Departures in Overlay Networks}},
doi = {10.1007/978-3-319-11764-5_4},
year = {2014},
}
@article{387,
abstract = {This article studies the design of medium access control (MAC) protocols for wireless networks that are provably robust against arbitrary and unpredictable disruptions (e.g., due to unintentional external interference from co-existing networks or due to jamming). We consider a wireless network consisting of a set of n honest and reliable nodes within transmission (and interference) range of each other, and we model the external disruptions with a powerful adaptive adversary. This adversary may know the protocol and its entire history and can use this knowledge to jam the wireless channel at will at any time. It is allowed to jam a (1 − )-fraction of the timesteps, for an arbitrary constant > 0 unknown to the nodes. The nodes cannot distinguish between the adversarial jamming or a collision of two or more messages that are sent at the same time. We demonstrate, for the first time, that there is a local-control MAC protocol requiring only very limited knowledge about the adversary and the network that achieves a constant (asymptotically optimal) throughput for the nonjammed time periods under any of the aforementioned adversarial strategies. The derived principles are also useful to build robust applications on top of the MAC layer, and we present an exemplary study for leader election, one of the most fundamental tasks in distributed computing.},
author = {Awerbuch, Baruch and Richa, Andrea W. and Scheideler, Christian and Schmid, Stefan and Zhang, Jin},
journal = {Transactions on Algorithms},
number = {4},
publisher = {ACM},
title = {{Principles of Robust Medium Access and an Application to Leader Election}},
doi = {10.1145/2635818},
year = {2014},
}
@article{464,
abstract = {Topological self-stabilization is an important concept to build robust open distributed systems (such as peer-to-peer systems) where nodes can organize themselves into meaningful network topologies. The goal is to devise distributed algorithms where nodes forward, insert, and delete links to neighboring nodes, and that converge quickly to such a desirable topology, independently of the initial network configuration. This article proposes a new model to study the parallel convergence time. Our model sheds light on the achievable parallelism by avoiding bottlenecks of existing models that can yield a distorted picture. As a case study, we consider local graph linearization—i.e., how to build a sorted list of the nodes of a connected graph in a distributed and self-stabilizing manner. In order to study the main structure and properties of our model, we propose two variants of a most simple local linearization algorithm. For each of these variants, we present analyses of the worst-case and bestcase parallel time complexities, as well as the performance under a greedy selection of the actions to be executed. It turns out that the analysis is non-trivial despite the simple setting, and to complement our formal insights we report on our experiments which indicate that the runtimes may be better in the average case.},
author = {Gall, Dominik and Jacob, Riko and Richa, Andrea W. and Scheideler, Christian and Schmid, Stefan and Täubig, Hanjo },
journal = {Theory of Computing Systems},
number = {1},
pages = {110--135},
publisher = {Springer},
title = {{A Note on the Parallel Runtime of Self-Stabilizing Graph Linearization}},
doi = {10.1007/s00224-013-9504-x},
year = {2014},
}
@article{1868,
author = {W. Richa, Andr{\'{e}}a and Scheideler, Christian and Schmid, Stefan and Zhang, Jin},
journal = {Distributed Computing},
number = {3},
pages = {159----171},
title = {{Competitive throughput in multi-hop wireless networks despite adaptive jamming}},
doi = {10.1007/s00446-012-0180-x},
year = {2013},
}
@article{1870,
author = {Mohd Nor, Rizal and Nesterenko, Mikhail and Scheideler, Christian},
journal = {Theor. Comput. Sci.},
pages = {119----129},
title = {{Corona: A stabilizing deterministic message-passing skip list}},
doi = {10.1016/j.tcs.2012.08.029},
year = {2013},
}
@inproceedings{542,
abstract = {We consider the problem of managing a dynamic heterogeneous storagesystem in a distributed way so that the amount of data assigned to a hostin that system is related to its capacity. Two central problems have to be solvedfor this: (1) organizing the hosts in an overlay network with low degree and diameterso that one can efficiently check the correct distribution of the data androute between any two hosts, and (2) distributing the data among the hosts so thatthe distribution respects the capacities of the hosts and can easily be adapted asthe set of hosts or their capacities change. We present distributed protocols forthese problems that are self-stabilizing and that do not need any global knowledgeabout the system such as the number of nodes or the overall capacity of thesystem. Prior to this work no solution was known satisfying these properties.},
author = {Kniesburges, Sebastian and Koutsopoulos, Andreas and Scheideler, Christian},
booktitle = {Proceedings of the 27th International Symposium on Distributed Computing (DISC)},
pages = {537--549},
title = {{CONE-DHT: A distributed self-stabilizing algorithm for a heterogeneous storage system}},
doi = {10.1007/978-3-642-41527-2_37},
year = {2013},
}
@article{1871,
author = {W. Richa, Andrea and Scheideler, Christian and Schmid, Stefan and Zhang, Jin},
journal = {IEEE/ACM Trans. Netw.},
number = {3},
pages = {760----771},
title = {{An Efficient and Fair MAC Protocol Robust to Reactive Interference}},
doi = {10.1109/TNET.2012.2210241},
year = {2013},
}
@inproceedings{513,
abstract = {This paper initiates the study of self-adjusting networks (or distributed data structures) whose topologies dynamically adapt to a communication pattern $\sigma$. We present a fully decentralized self-adjusting solution called SplayNet. A SplayNet is a distributed generalization of the classic splay tree concept. It ensures short paths (which can be found using local-greedy routing) between communication partners while minimizing topological rearrangements. We derive an upper bound for the amortized communication cost of a SplayNet based on empirical entropies of $\sigma$, and show that SplayNets have several interesting convergence properties. For instance, SplayNets features a provable online optimality under special requests scenarios. We also investigate the optimal static network and prove different lower bounds for the average communication cost based on graph cuts and on the empirical entropy of the communication pattern $\sigma$. From these lower bounds it follows, e.g., that SplayNets are optimal in scenarios where the requests follow a product distribution as well. Finally, this paper shows that in contrast to the Minimum Linear Arrangement problem which is generally NP-hard, the optimal static tree network can be computed in polynomial time for any guest graph, despite the exponentially large graph family. We complement our formal analysis with a small simulation study on a Facebook graph.},
author = {Avin, Chen and Häupler, Bernhard and Lotker, Zvi and Scheideler, Christian and Schmid, Stefan},
booktitle = {Proceedings of the 27th IEEE International Parallel and Distributed Processing Symposium (IPDPS)},
pages = {395--406},
title = {{Locally Self-Adjusting Tree Networks}},
doi = {10.1109/IPDPS.2013.40},
year = {2013},
}
@inproceedings{519,
abstract = {In this work we present the first scalable distributed information system,i.e., a system with low storage overhead, that is provably robust againstDenial-of-Service (DoS) attacks by a current insider. We allow acurrent insider to have complete knowledge about the information systemand to have the power to block any \epsilon-fraction of its serversby a DoS-attack, where \epsilon can be chosen up to a constant. The taskof the system is to serve any collection of lookup requests with at most oneper non-blocked server in an efficient way despite this attack. Previously,scalable solutions were only known for DoS-attacks of past insiders, where apast insider only has complete knowledge about some past time pointt_0 of the information system. Scheideler et al. (DISC 2007, SPAA 2009) showedthat in this case it is possible to design an information system so that anyinformation that was inserted or last updated after t_0 is safe against a DoS-attack. But their constructions would not work at all for a current insider. The key idea behindour IRIS system is to make extensive use of coding. More precisely, we presenttwo alternative distributed coding strategies with an at most logarithmicstorage overhead that can handle up to a constant fraction of blocked servers.},
author = {Eikel, Martina and Scheideler, Christian},
booktitle = {Proceedings of the 25th ACM Symposium on Parallelism in Algorithms and Architectures (SPAA)},
pages = {119--129},
title = {{IRIS: A Robust Information System Against Insider DoS-Attacks}},
doi = {10.1145/2486159.2486186},
year = {2013},
}
@inproceedings{564,
abstract = {We consider the problem of resource discovery in distributed systems. In particular we give an algorithm, such that each node in a network discovers the add ress of any other node in the network. We model the knowledge of the nodes as a virtual overlay network given by a directed graph such that complete knowledge of all nodes corresponds to a complete graph in the overlay network. Although there are several solutions for resource discovery, our solution is the first that achieves worst-case optimal work for each node, i.e. the number of addresses (O(n)) or bits (O(nlogn)) a node receives or sendscoincides with the lower bound, while ensuring only a linearruntime (O(n)) on the number of rounds.},
author = {Kniesburges, Sebastian and Koutsopoulos, Andreas and Scheideler, Christian},
booktitle = {Proceedings of 20th International Colloqium on Structural Information and Communication Complexity (SIROCCO)},
pages = {165--176},
title = {{A Deterministic Worst-Case Message Complexity Optimal Solution for Resource Discovery}},
doi = {10.1007/978-3-319-03578-9_14},
year = {2013},
}
@article{476,
abstract = {An elementary h-route ow, for an integer h 1, is a set of h edge- disjoint paths between a source and a sink, each path carrying a unit of ow, and an h-route ow is a non-negative linear combination of elementary h-routeows. An h-route cut is a set of edges whose removal decreases the maximum h-route ow between a given source-sink pair (or between every source-sink pair in the multicommodity setting) to zero. The main result of this paper is an approximate duality theorem for multicommodity h-route cuts and ows, for h 3: The size of a minimum h-route cut is at least f=h and at most O(log4 k f) where f is the size of the maximum h-routeow and k is the number of commodities. The main step towards the proof of this duality is the design and analysis of a polynomial-time approximation algorithm for the minimum h-route cut problem for h = 3 that has an approximation ratio of O(log4 k). Previously, polylogarithmic approximation was known only for h-route cuts for h 2. A key ingredient of our algorithm is a novel rounding technique that we call multilevel ball-growing. Though the proof of the duality relies on this algorithm, it is not a straightforward corollary of it as in the case of classical multicommodity ows and cuts. Similar results are shown also for the sparsest multiroute cut problem.},
author = {Kolman, Petr and Scheideler, Christian},
journal = {Theory of Computing Systems},
number = {2},
pages = {341--363},
publisher = {Springer},
title = {{Towards Duality of Multicommodity Multiroute Cuts and Flows: Multilevel Ball-Growing}},
doi = {10.1007/s00224-013-9454-3},
year = {2013},
}
@article{1882,
author = {Dolev, Shlomi and Scheideler, Christian},
journal = {Theor. Comput. Sci.},
pages = {1},
title = {{Editorial for Algorithmic Aspects of Wireless Sensor Networks}},
doi = {10.1016/j.tcs.2012.07.012},
year = {2012},
}
@article{574,
abstract = {We present Tiara — a self-stabilizing peer-to-peer network maintenance algorithm. Tiara is truly deterministic which allows it to achieve exact performance bounds. Tiara allows logarithmic searches and topology updates. It is based on a novel sparse 0-1 skip list. We then describe its extension to a ringed structure and to a skip-graph.Key words: Peer-to-peer networks, overlay networks, self-stabilization.},
author = {Clouser, Thomas and Nesterenko, Mikhail and Scheideler, Christian},
journal = {Theoretical Computer Science},
pages = {18--35},
publisher = {Elsevier},
title = {{Tiara: A self-stabilizing deterministic skip list and skip graph}},
doi = {10.1016/j.tcs.2011.12.079},
year = {2012},
}
@article{579,
abstract = {A left-to-right maximum in a sequence of n numbers s_1, …, s_n is a number that is strictly larger than all preceding numbers. In this article we present a smoothed analysis of the number of left-to-right maxima in the presence of additive random noise. We show that for every sequence of n numbers s_i ∈ [0,1] that are perturbed by uniform noise from the interval [-ε,ε], the expected number of left-to-right maxima is Θ(&sqrt;n/ε + log n) for ε>1/n. For Gaussian noise with standard deviation σ we obtain a bound of O((log3/2 n)/σ + log n).We apply our results to the analysis of the smoothed height of binary search trees and the smoothed number of comparisons in the quicksort algorithm and prove bounds of Θ(&sqrt;n/ε + log n) and Θ(n/ε+1&sqrt;n/ε + n log n), respectively, for uniform random noise from the interval [-ε,ε]. Our results can also be applied to bound the smoothed number of points on a convex hull of points in the two-dimensional plane and to smoothed motion complexity, a concept we describe in this article. We bound how often one needs to update a data structure storing the smallest axis-aligned box enclosing a set of points moving in d-dimensional space.},
author = {Damerow, Valentina and Manthey, Bodo and Meyer auf der Heide, Friedhelm and Räcke, Harald and Scheideler, Christian and Sohler, Christian and Tantau, Till},
journal = {Transactions on Algorithms},
number = {3},
pages = {30},
publisher = {ACM},
title = {{Smoothed analysis of left-to-right maxima with applications}},
doi = {10.1145/2229163.2229174},
year = {2012},
}
@inproceedings{581,
abstract = {Nanoparticles are getting more and more in the focus of the scientic community since the potential for the development of very small particles interacting with each other and completing medical and other tasks is getting bigger year by year. In this work we introduce a distributed local algorithm for arranging a set of nanoparticles on the discrete plane into specic geometric shapes, for instance a rectangle. The concept of a particle we use can be seen as a simple mobile robot with the following restrictions: it can only view the state of robots it is physically connected to, is anonymous, has only a constant size memory, can only move by using other particles as an anchor point on which it pulls itself alongside, and it operates in Look-Compute-Move cycles. The main result of this work is the presentation of a random distributed local algorithm which transforms any given connected set of particles into a particular geometric shape. As an example we provide a version of this algorithm for forming a rectangle with an arbitrary predened aspect ratio. To the best of our knowledge this is the rst work that considers arrangement problems for these types of robots.},
author = {Drees, Maximilian and Hüllmann (married name: Eikel), Martina and Koutsopoulos, Andreas and Scheideler, Christian},
booktitle = {Proceedings of the 26th IEEE International Parallel and Distributed Processing Symposium (IPDPS)},
pages = {1272--1283},
title = {{Self-Organizing Particle Systems}},
doi = {10.1109/IPDPS.2012.116},
year = {2012},
}
@inproceedings{625,
abstract = {This paper initiates the study of self-adjusting distributed data structures for networks. In particular, we present SplayNets: a binary search tree based network that is self-adjusting to routing request.We derive entropy bounds on the amortized routing cost and show that our splaying algorithm has some interesting properties.},
author = {Schmid, Stefan and Avin, Chen and Scheideler, Christian and Häupler, Bernhard and Lotker, Zvi},
booktitle = {Proceedings of the 26th International Symposium on Distributed Computing (DISC)},
pages = {439--440},
title = {{Brief Announcement: SplayNets - Towards Self-Adjusting Distributed Data Structures}},
doi = {10.1007/978-3-642-33651-5_47},
year = {2012},
}