@inproceedings{4565,
author = {Jung, Daniel and Kolb, Christina and Scheideler, Christian and Sundermeier, Jannik},
booktitle = {Proceedings of the 30th on Symposium on Parallelism in Algorithms and Architectures (SPAA)},
isbn = {9781450357999},
location = {Wien},
publisher = {ACM Press},
title = {{Brief Announcement: Competitive Routing in Hybrid Communication Networks}},
doi = {10.1145/3210377.3210663},
year = {2018},
}
@inproceedings{1163,
abstract = {In this paper we present two major results:
First, we introduce the first self-stabilizing version of a supervised overlay network (as introduced in~\cite{DBLP:conf/ispan/KothapalliS05}) by presenting a self-stabilizing supervised skip ring.
Secondly, we show how to use the self-stabilizing supervised skip ring to construct an efficient self-stabilizing publish-subscribe system.
That is, in addition to stabilizing the overlay network, every subscriber of a topic will eventually know all of the publications that have been issued so far for that topic. The communication work needed to processes a subscribe or unsubscribe operation is just a constant in a legitimate state, and the communication work of checking whether the system is still in a legitimate state is just a constant on expectation for the supervisor as well as any process in the system.
},
author = {Feldmann, Michael and Kolb, Christina and Scheideler, Christian and Strothmann, Thim Frederik},
booktitle = {Proceedings of the 32nd IEEE International Parallel & Distributed Processing Symposium (IPDPS)},
keyword = {Topological Self-stabilization, Supervised Overlay, Publish-Subscribe System},
location = {Vancouver},
publisher = {IEEE},
title = {{Self-Stabilizing Supervised Publish-Subscribe Systems}},
doi = {10.1109/IPDPS.2018.00114},
year = {2018},
}
@inproceedings{5216,
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. To rigorously study self-stabilizing solutions to this problem, the Finite Departure Problem (FDP) has been proposed [9]. In the FDP we are given a network of processes in an arbitrary state, and the goal is to eventually arrive at (and stay in) a state in which all leaving processes irrevocably decided to leave the system while for all weakly-connected components in the initial overlay network, all staying processes in that component will still form a weakly connected component. In the standard interconnection model, the FDP is known to be unsolvable by local control protocols, so oracles have been investigated that allow the problem to be solved [9]. To avoid the use of oracles, we introduce a new interconnection model based on relays. Despite the relay model appearing to be rather restrictive, we show that it is universal, i.e., it is possible to transform any weakly-connected topology into any other weakly-connected topology, which is important for being a useful interconnection model for overlay networks. Apart from this, our model allows processes to grant and revoke access rights, which is why we believe it to be of interest beyond the scope of this paper. We show how to implement the relay layer in a self-stabilizing way and identify properties protocols need to satisfy so that the relay layer can recover while serving protocol requests.},
author = {Scheideler, Christian and Setzer, Alexander},
booktitle = {Proceedings of the 20th International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS 2018)},
location = {Tokyo, Japan},
title = {{Relays: A New Approach for the Finite Departure Problem in Overlay Networks}},
doi = {10.1007/978-3-030-03232-6_16},
year = {2018},
}
@inproceedings{1164,
abstract = {We propose a distributed protocol for a queue, called Skueue, which spreads its data fairly onto multiple processes, avoiding bottlenecks in high throughput scenarios.
Skueuecan be used in highly dynamic environments, through the addition of join and leave requests to the standard queue operations enqueue and dequeue.
Furthermore Skueue satisfies sequential consistency in the asynchronous message passing model.
Scalability is achieved by aggregating multiple requests to a batch, which can then be processed in a distributed fashion without hurting the queue semantics.
Operations in Skueue need a logarithmic number of rounds w.h.p. until they are processed, even under a high rate of incoming requests.},
author = {Feldmann, Michael and Scheideler, Christian and Setzer, Alexander},
booktitle = {Proceedings of the 32nd IEEE International Parallel & Distributed Processing Symposium (IPDPS)},
location = {Vancouver},
publisher = {IEEE},
title = {{Skueue: A Scalable and Sequentially Consistent Distributed Queue}},
doi = {10.1109/IPDPS.2018.00113},
year = {2018},
}
@article{1796,
author = {J. Daymude, Joshua and Derakhshandeh, Zahra and Gmyr, Robert and Porter, Alexandra and W. Richa, Andrea and Scheideler, Christian and Strothmann, Thim Frederik},
journal = {Natural Computing},
number = {1},
pages = {81----96},
title = {{On the runtime of universal coating for programmable matter}},
doi = {10.1007/s11047-017-9658-6},
year = {2018},
}
@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{13652,
author = {Hinnenthal, Kristian and Scheideler, Christian and Struijs, Martijn},
booktitle = {33rd International Symposium on Distributed Computing (DISC 2019)},
title = {{Fast Distributed Algorithms for LP-Type Problems of Low Dimension}},
doi = {10.4230/LIPICS.DISC.2019.23},
year = {2019},
}
@inproceedings{15627,
author = {Augustine, John and Hinnenthal, Kristian and Kuhn, Fabian and Scheideler, Christian and Schneider, Philipp},
booktitle = {Proceedings of the Fourteenth Annual ACM-SIAM Symposium on Discrete Algorithms},
isbn = {9781611975994},
pages = {1280--1299},
title = {{Shortest Paths in a Hybrid Network Model}},
doi = {10.1137/1.9781611975994.78},
year = {2019},
}
@inproceedings{6976,
abstract = {We investigate the maintenance of overlay networks under massive churn, i.e.
nodes joining and leaving the network. We assume an adversary that may churn a
constant fraction $\alpha n$ of nodes over the course of $\mathcal{O}(\log n)$
rounds. In particular, the adversary has an almost up-to-date information of
the network topology as it can observe an only slightly outdated topology that
is at least $2$ rounds old. Other than that, we only have the provably minimal
restriction that new nodes can only join the network via nodes that have taken
part in the network for at least one round.
Our contributions are as follows: First, we show that it is impossible to
maintain a connected topology if adversary has up-to-date information about the
nodes' connections. Further, we show that our restriction concerning the join
is also necessary. As our main result present an algorithm that constructs a
new overlay- completely independent of all previous overlays - every $2$
rounds. Furthermore, each node sends and receives only $\mathcal{O}(\log^3 n)$
messages each round. As part of our solution we propose the Linearized DeBruijn
Swarm (LDS), a highly churn resistant overlay, which will be maintained by the
algorithm. However, our approaches can be transferred to a variety of classical
P2P Topologies where nodes are mapped into the $[0,1)$-interval.},
author = {Götte, Thorsten and Vijayalakshmi, Vipin Ravindran and Scheideler, Christian},
booktitle = {Proceedings of the 2019 IEEE 33rd International Parallel and Distributed Processing Symposium (IPDPS '19)},
location = {Rio de Janeiro, Brazil},
publisher = {IEEE},
title = {{Always be Two Steps Ahead of Your Enemy - Maintaining a Routable Overlay under Massive Churn with an Almost Up-to-date Adversary}},
year = {2019},
}
@inproceedings{8871,
author = {Augustine, John and Ghaffari, Mohsen and Gmyr, Robert and Hinnenthal, Kristian and Kuhn, Fabian and Li, Jason and Scheideler, Christian},
booktitle = {Proceedings of the 31st ACM Symposium on Parallelism in Algorithms and Architectures},
pages = {69----79},
publisher = {ACM},
title = {{Distributed Computation in Node-Capacitated Networks}},
doi = {10.1145/3323165.3323195},
year = {2019},
}
@article{14830,
author = {Gmyr, Robert and Lefevre, Jonas and Scheideler, Christian},
journal = {Theory Comput. Syst.},
number = {2},
pages = {177--199},
title = {{Self-Stabilizing Metric Graphs}},
doi = {10.1007/s00224-017-9823-4},
volume = {63},
year = {2019},
}
@inproceedings{10586,
abstract = {We consider the problem of transforming a given graph G_s into a desired graph G_t by applying a minimum number of primitives from a particular set of local graph transformation primitives. These primitives are local in the sense that each node can apply them based on local knowledge and by affecting only its 1-neighborhood. Although the specific set of primitives we consider makes it possible to transform any (weakly) connected graph into any other (weakly) connected graph consisting of the same nodes, they cannot disconnect the graph or introduce new nodes into the graph, making them ideal in the context of supervised overlay network transformations. We prove that computing a minimum sequence of primitive applications (even centralized) for arbitrary G_s and G_t is NP-hard, which we conjecture to hold for any set of local graph transformation primitives satisfying the aforementioned properties. On the other hand, we show that this problem admits a polynomial time algorithm with a constant approximation ratio.},
author = {Scheideler, Christian and Setzer, Alexander},
booktitle = {Proceedings of the 46th International Colloquium on Automata, Languages, and Programming},
keyword = {Graphs transformations, NP-hardness, approximation algorithms},
location = {Patras, Greece},
pages = {150:1----150:14},
publisher = {Dagstuhl Publishing},
title = {{On the Complexity of Local Graph Transformations}},
doi = {10.4230/LIPICS.ICALP.2019.150},
volume = {132},
year = {2019},
}
@inproceedings{7636,
abstract = {Self-stabilizing overlay networks have the advantage of being able to recover from illegal states and faults.
However, the majority of these networks cannot give any guarantees on their functionality while the recovery process is going on.
We are especially interested in searchability, i.e., the functionality that search messages for a specific node are answered successfully if a node exists in the network.
In this paper we investigate overlay networks that ensure the maintenance of monotonic searchability while the self-stabilization is going on.
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 extend the existing research by focusing on skip graphs and present a solution for two scenarios: (i) the goal topology is a super graph of the perfect skip graph and (ii) the goal topology is exactly the perfect skip graph.
},
author = {Luo, Linghui and Scheideler, Christian and Strothmann, Thim Frederik},
booktitle = {Proceedings of the 2019 IEEE 33rd International Parallel and Distributed Processing Symposium (IPDPS '19)},
location = {Rio de Janeiro, Brazil},
title = {{MultiSkipGraph: A Self-stabilizing Overlay Network that Maintains Monotonic Searchability}},
year = {2019},
}
@inproceedings{13182,
abstract = {We consider congestion control in peer-to-peer distributed systems.
The problem can be reduced to the following scenario: Consider a set $V$ of $n$ peers (called \emph{clients} in this paper) that want to send messages to a fixed common peer (called \emph{server} in this paper).
We assume that each client $v \in V$ sends a message with probability $p(v) \in [0,1)$ and the server has a capacity of $\sigma \in \mathbb{N}$, i.e., it can recieve at most $\sigma$ messages per round and excess messages are dropped.
The server can modify these probabilities when clients send messages.
Ideally, we wish to converge to a state with $\sum p(v) = \sigma$ and $p(v) = p(w)$ for all $v,w \in V$.
We propose a \emph{loosely} self-stabilizing protocol with a slightly relaxed legitimate state.
Our protocol lets the system converge from \emph{any} initial state to a state where $\sum p(v) \in \left[\sigma \pm \epsilon\right]$ and $|p(v)-p(w)| \in O(\frac{1}{n})$.
This property is then maintained for $\Omega(n^{\mathfrak{c}})$ rounds in expectation.
In particular, the initial client probabilities and server variables are not necessarily well-defined, i.e., they may have arbitrary values.
Our protocol uses only $O(W + \log n)$ bits of memory where $W$ is length of node identifiers, making it very lightweight.
Finally we state a lower bound on the convergence time an see that our protocol performs asymptotically optimal (up to some polylogarithmic factor).
},
author = {Feldmann, Michael and Götte, Thorsten and Scheideler, Christian},
booktitle = {Proceedings of the 21st International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS)},
pages = {149--164},
publisher = {Springer, Cham},
title = {{A Loosely Self-stabilizing Protocol for Randomized Congestion Control with Logarithmic Memory}},
doi = {https://doi.org/10.1007/978-3-030-34992-9_13},
year = {2019},
}
@inproceedings{12944,
author = {Götte, Thorsten and Hinnenthal, Kristian and Scheideler, Christian},
booktitle = {Structural Information and Communication Complexity},
title = {{Faster Construction of Overlay Networks}},
doi = {10.1007/978-3-030-24922-9_18},
year = {2019},
}
@inproceedings{14539,
author = {Castenow, Jannik and Kolb, Christina and Scheideler, Christian},
booktitle = {Proceedings of the 26th International Colloquium on Structural Information and Communication Complexity (SIROCCO)},
location = {L'Aquila, Italy},
pages = {345--348},
title = {{A Bounding Box Overlay for Competitive Routing in Hybrid Communication Networks}},
doi = {10.1007/978-3-030-24922-9\_26},
year = {2019},
}
@inproceedings{8534,
abstract = {We propose two protocols for distributed priority queues (denoted by 'heap' for simplicity in this paper) called SKEAP and SEAP. SKEAP realizes a distributed heap for a constant amount of priorities and SEAP one for an arbitrary amount. Both protocols build on an overlay, which induces an aggregation tree on which heap operations are aggregated in batches, ensuring that our protocols scale even for a high rate of incoming requests. As part of SEAP we provide a novel distributed protocol for the k-selection problem that runs in time O(log n) w.h.p. SKEAP guarantees sequential consistency for its heap operations, while SEAP guarantees serializability. SKEAP and SEAP provide logarithmic runtimes w.h.p. on all their operations.
SKEAP and SEAP provide logarithmic runtimes w.h.p. on all their operations with SEAP having to use only O(log n) bit messages.},
author = {Feldmann, Michael and Scheideler, Christian},
booktitle = {Proceedings of the 31st ACM Symposium on Parallelism in Algorithms and Architectures (SPAA)},
pages = {287----296},
publisher = {ACM},
title = {{Skeap & Seap: Scalable Distributed Priority Queues for Constant and Arbitrary Priorities}},
doi = {10.1145/3323165.3323193},
year = {2019},
}
@inbook{9599,
author = {Daymude, Joshua J. and Hinnenthal, Kristian and Richa, Andréa W. and Scheideler, Christian},
booktitle = {Distributed Computing by Mobile Entities, Current Research in Moving and Computing.},
pages = {615--681},
publisher = {Springer, Cham},
title = {{Computing by Programmable Particles}},
doi = {https://doi.org/10.1007/978-3-030-11072-7_22},
year = {2019},
}
@inproceedings{16346,
author = {Daymude, Joshua J. and Gmyr, Robert and Hinnenthal, Kristian and Kostitsyna, Irina and Scheideler, Christian and Richa, Andréa W.},
booktitle = {Proceedings of the 21st International Conference on Distributed Computing and Networking},
isbn = {9781450377515},
title = {{Convex Hull Formation for Programmable Matter}},
doi = {10.1145/3369740.3372916},
year = {2020},
}
@article{17808,
author = {Gmyr, Robert and Hinnenthal, Kristian and Kostitsyna, Irina and Kuhn, Fabian and Rudolph, Dorian and Scheideler, Christian and Strothmann, Thim},
journal = {Nat. Comput.},
number = {2},
pages = {375--390},
title = {{Forming tile shapes with simple robots}},
doi = {10.1007/s11047-019-09774-2},
volume = {19},
year = {2020},
}
@inproceedings{20755,
abstract = {We consider the problem of computing shortest paths in \emph{hybrid networks}, in which nodes can make use of different communication modes. For example, mobile phones may use ad-hoc connections via Bluetooth or Wi-Fi in addition to the cellular network to solve tasks more efficiently. Like in this case, the different communication modes may differ considerably in range, bandwidth, and flexibility. We build upon the model of Augustine et al. [SODA '20], which captures these differences by a \emph{local} and a \emph{global} mode. Specifically, the local edges model a fixed communication network in which $O(1)$ messages of size $O(\log n)$ can be sent over every edge in each synchronous round. The global edges form a clique, but nodes are only allowed to send and receive a total of at most $O(\log n)$ messages over global edges, which restricts the nodes to use these edges only very sparsely.
We demonstrate the power of hybrid networks by presenting algorithms to compute Single-Source Shortest Paths and the diameter very efficiently in \emph{sparse graphs}. Specifically, we present exact $O(\log n)$ time algorithms for cactus graphs (i.e., graphs in which each edge is contained in at most one cycle), and $3$-approximations for graphs that have at most $n + O(n^{1/3})$ edges and arboricity $O(\log n)$. For these graph classes, our algorithms provide exponentially faster solutions than the best known algorithms for general graphs in this model.
Beyond shortest paths, we also provide a variety of useful tools and techniques for hybrid networks, which may be of independent interest.
},
author = {Feldmann, Michael and Hinnenthal, Kristian and Scheideler, Christian},
booktitle = {Proceedings of the 24th International Conference on Principles of Distributed Systems (OPODIS)},
publisher = {Schloss Dagstuhl - Leibniz-Zentrum für Informatik},
title = {{Fast Hybrid Network Algorithms for Shortest Paths in Sparse Graphs}},
year = {2020},
}
@article{16902,
abstract = {The maintenance of efficient and robust overlay networks is one
of the most fundamental and reoccurring themes in networking.
This paper presents a survey of state-of-the-art
algorithms to design and repair overlay networks in a distributed
manner. In particular, we discuss basic algorithmic primitives
to preserve connectivity, review algorithms for the fundamental
problem of graph linearization, and then survey self-stabilizing
algorithms for metric and scalable topologies.
We also identify open problems and avenues for future research.
},
author = {Feldmann, Michael and Scheideler, Christian and Schmid, Stefan},
journal = {ACM Computing Surveys},
publisher = {ACM},
title = {{Survey on Algorithms for Self-Stabilizing Overlay Networks}},
doi = {10.1145/3397190},
year = {2020},
}
@inproceedings{15169,
author = {Castenow, Jannik and Kolb, Christina and Scheideler, Christian},
booktitle = {Proceedings of the 21st International Conference on Distributed Computing and Networking (ICDCN)},
location = {Kolkata, Indien},
publisher = {ACM},
title = {{A Bounding Box Overlay for Competitive Routing in Hybrid Communication Networks}},
year = {2020},
}
@inproceedings{16903,
abstract = {We consider the clock synchronization problem in the (discrete) beeping model: Given a network of $n$ nodes with each node having a clock value $\delta(v) \in \{0,\ldots T-1\}$, the goal is to synchronize the clock values of all nodes such that they have the same value in any round.
As is standard in clock synchronization, we assume \emph{arbitrary activations} for all nodes, i.e., the nodes start their protocol at an arbitrary round (not limited to $\{0,\ldots,T-1\}$).
We give an asymptotically optimal algorithm that runs in $4D + \Bigl\lfloor \frac{D}{\lfloor T/4 \rfloor} \Bigr \rfloor \cdot (T \mod 4) = O(D)$ rounds, where $D$ is the diameter of the network.
Once all nodes are in sync, they beep at the same round every $T$ rounds.
The algorithm drastically improves on the $O(T D)$-bound of \cite{firefly_sync} (where $T$ is required to be at least $4n$, so the bound is no better than $O(nD)$).
Our algorithm is very simple as nodes only have to maintain $3$ bits in addition to the $\lceil \log T \rceil$ bits needed to maintain the clock.
Furthermore we investigate the complexity of \emph{self-stabilizing} solutions for the clock synchronization problem: We first show lower bounds of $\Omega(\max\{T,n\})$ rounds on the runtime and $\Omega(\log(\max\{T,n\}))$ bits of memory required for any such protocol.
Afterwards we present a protocol that runs in $O(\max\{T,n\})$ rounds using at most $O(\log(\max\{T,n\}))$ bits at each node, which is asymptotically optimal with regards to both, runtime and memory requirements.},
author = {Feldmann, Michael and Khazraei, Ardalan and Scheideler, Christian},
booktitle = {Proceedings of the 32nd ACM Symposium on Parallelism in Algorithms and Architectures (SPAA)},
publisher = {ACM},
title = {{Time- and Space-Optimal Discrete Clock Synchronization in the Beeping Model}},
doi = {10.1145/3350755.3400246},
year = {2020},
}