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Documents authored by Zălinescu, Eugen

Found 2 Possible Name Variants:

Zalinescu, Eugen

Document
DOI: 10.4230/OASIcs.FAB.2021.1
Tenderbake - A Solution to Dynamic Repeated Consensus for Blockchains

Authors: Lăcrămioara Aştefănoaei, Pierre Chambart, Antonella Del Pozzo, Thibault Rieutord, Sara Tucci-Piergiovanni, and Eugen Zălinescu

Published in: OASIcs, Volume 92, 4th International Symposium on Foundations and Applications of Blockchain 2021 (FAB 2021)

Abstract
First-generation blockchains provide probabilistic finality: a block can be revoked, albeit the probability decreases as the block "sinks" deeper into the chain. Recent proposals revisited committee-based BFT consensus to provide deterministic finality: as soon as a block is validated, it is never revoked. A distinguishing characteristic of these second-generation blockchains over classical BFT protocols is that committees change over time as the participation and the blockchain state evolve. In this paper, we push forward in this direction by proposing a formalization of the Dynamic Repeated Consensus problem and by providing generic procedures to solve it in the context of blockchains. Our approach is modular in that one can plug in different synchronizers and single-shot consensus. To offer a complete solution, we provide a concrete instantiation, called {{Tenderbake}}, and present a blockchain synchronizer and a single-shot consensus algorithm, working in a Byzantine and partially synchronous system model with eventually synchronous clocks. In contrast to recent proposals, our methodology is driven by the need to bound the message buffers. This is essential in preventing spamming and run-time memory errors. Moreover, {{Tenderbake}} processes can synchronize with each other without exchanging messages, leveraging instead the information stored in the blockchain.
Cite as

Lăcrămioara Aştefănoaei, Pierre Chambart, Antonella Del Pozzo, Thibault Rieutord, Sara Tucci-Piergiovanni, and Eugen Zălinescu. Tenderbake - A Solution to Dynamic Repeated Consensus for Blockchains. In 4th International Symposium on Foundations and Applications of Blockchain 2021 (FAB 2021). Open Access Series in Informatics (OASIcs), Volume 92, pp. 1:1-1:23, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2021)

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@InProceedings{astefanoaei_et_al:OASIcs.FAB.2021.1,
  author =	{A\c{s}tef\u{a}noaei, L\u{a}cr\u{a}mioara and Chambart, Pierre and Del Pozzo, Antonella and Rieutord, Thibault and Tucci-Piergiovanni, Sara and Z\u{a}linescu, Eugen},
  title =	{{Tenderbake - A Solution to Dynamic Repeated Consensus for Blockchains}},
  booktitle =	{4th International Symposium on Foundations and Applications of Blockchain 2021 (FAB 2021)},
  pages =	{1:1--1:23},
  series =	{Open Access Series in Informatics (OASIcs)},
  ISBN =	{978-3-95977-196-2},
  ISSN =	{2190-6807},
  year =	{2021},
  volume =	{92},
  editor =	{Gramoli, Vincent and Sadoghi, Mohammad},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/OASIcs.FAB.2021.1},
  URN =		{urn:nbn:de:0030-drops-139877},
  doi =		{10.4230/OASIcs.FAB.2021.1},
  annote =	{Keywords: Blockchain, BFT-Consensus, Dynamic Repeated Consensus}
}
Document
DOI: 10.4230/LIPIcs.FSTTCS.2015.590
Failure-aware Runtime Verification of Distributed Systems

Authors: David Basin, Felix Klaedtke, and Eugen Zalinescu

Published in: LIPIcs, Volume 45, 35th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2015)

Abstract
Prior runtime-verification approaches for distributed systems are limited as they do not account for network failures and they assume that system messages are received in the order they are sent. To overcome these limitations, we present an online algorithm for verifying observed system behavior at runtime with respect to specifications written in the real-time logic MTL that efficiently handles out-of-order message deliveries and operates in the presence of failures. Our algorithm uses a three-valued semantics for MTL, where the third truth value models knowledge gaps, and it resolves knowledge gaps as it propagates Boolean values through the formula structure. We establish the algorithm's soundness and provide completeness guarantees. We also show that it supports distributed system monitoring, where multiple monitors cooperate and exchange their observations and conclusions.
Cite as

David Basin, Felix Klaedtke, and Eugen Zalinescu. Failure-aware Runtime Verification of Distributed Systems. In 35th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2015). Leibniz International Proceedings in Informatics (LIPIcs), Volume 45, pp. 590-603, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2015)

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@InProceedings{basin_et_al:LIPIcs.FSTTCS.2015.590,
  author =	{Basin, David and Klaedtke, Felix and Zalinescu, Eugen},
  title =	{{Failure-aware Runtime Verification of Distributed Systems}},
  booktitle =	{35th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2015)},
  pages =	{590--603},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-939897-97-2},
  ISSN =	{1868-8969},
  year =	{2015},
  volume =	{45},
  editor =	{Harsha, Prahladh and Ramalingam, G.},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.FSTTCS.2015.590},
  URN =		{urn:nbn:de:0030-drops-56194},
  doi =		{10.4230/LIPIcs.FSTTCS.2015.590},
  annote =	{Keywords: Runtime verification, monitoring algorithm, real-time logics, multi-valued semantics, distributed systems, asynchronous communication}
}
Document
DOI: 10.4230/OASIcs.TrustworthySW.2006.691
Relating two standard notions of secrecy

Authors: Eugen Zalinescu, Véronique Cortier, and Michaël Rusinowitch

Published in: OASIcs, Volume 3, Workshop on Trustworthy Software (2006)

Abstract
Two styles of definitions are usually considered to express that a security protocol preserves the confidentiality of a data { t s}. Reach-ability-based secrecy means that { t s} should never be disclosed while equi-valence-based secrecy states that two executions of a protocol with distinct instances for { t s} should be indistinguishable to an attacker. Although the second formulation ensures a higher level of security and is closer to cryptographic notions of secrecy, decidability results and automatic tools have mainly focused on the first definition so far. This paper initiates a systematic investigation of situations where syntactic secrecy entails strong secrecy. We show that in the passive case, reachability-based secrecy actually implies equivalence-based secrecy for signatures, symmetric and asymmetric encryption provided that the primitives are probabilistic. For active adversaries in the case of symmetric encryption, we provide sufficient (and rather tight) conditions on the protocol for this implication to hold.
Cite as

Eugen Zalinescu, Véronique Cortier, and Michaël Rusinowitch. Relating two standard notions of secrecy. In Workshop on Trustworthy Software. Open Access Series in Informatics (OASIcs), Volume 3, pp. 1-29, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2006)

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@InProceedings{zalinescu_et_al:OASIcs.TrustworthySW.2006.691,
  author =	{Zalinescu, Eugen and Cortier, V\'{e}ronique and Rusinowitch, Micha\"{e}l},
  title =	{{Relating two standard notions of secrecy}},
  booktitle =	{Workshop on Trustworthy Software},
  pages =	{1--29},
  series =	{Open Access Series in Informatics (OASIcs)},
  ISBN =	{978-3-939897-02-6},
  ISSN =	{2190-6807},
  year =	{2006},
  volume =	{3},
  editor =	{Autexier, Serge and Merz, Stephan and van der Torre, Leon and Wilhelm, Reinhard and Wolper, Pierre},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/OASIcs.TrustworthySW.2006.691},
  URN =		{urn:nbn:de:0030-drops-6911},
  doi =		{10.4230/OASIcs.TrustworthySW.2006.691},
  annote =	{Keywords: Verification, security protocols, secrecy, applied-pi calculus}
}

Zălinescu, Eugen

Document
DOI: 10.4230/OASIcs.FAB.2021.1
Tenderbake - A Solution to Dynamic Repeated Consensus for Blockchains

Authors: Lăcrămioara Aştefănoaei, Pierre Chambart, Antonella Del Pozzo, Thibault Rieutord, Sara Tucci-Piergiovanni, and Eugen Zălinescu

Published in: OASIcs, Volume 92, 4th International Symposium on Foundations and Applications of Blockchain 2021 (FAB 2021)

Abstract
First-generation blockchains provide probabilistic finality: a block can be revoked, albeit the probability decreases as the block "sinks" deeper into the chain. Recent proposals revisited committee-based BFT consensus to provide deterministic finality: as soon as a block is validated, it is never revoked. A distinguishing characteristic of these second-generation blockchains over classical BFT protocols is that committees change over time as the participation and the blockchain state evolve. In this paper, we push forward in this direction by proposing a formalization of the Dynamic Repeated Consensus problem and by providing generic procedures to solve it in the context of blockchains. Our approach is modular in that one can plug in different synchronizers and single-shot consensus. To offer a complete solution, we provide a concrete instantiation, called {{Tenderbake}}, and present a blockchain synchronizer and a single-shot consensus algorithm, working in a Byzantine and partially synchronous system model with eventually synchronous clocks. In contrast to recent proposals, our methodology is driven by the need to bound the message buffers. This is essential in preventing spamming and run-time memory errors. Moreover, {{Tenderbake}} processes can synchronize with each other without exchanging messages, leveraging instead the information stored in the blockchain.
Cite as

Lăcrămioara Aştefănoaei, Pierre Chambart, Antonella Del Pozzo, Thibault Rieutord, Sara Tucci-Piergiovanni, and Eugen Zălinescu. Tenderbake - A Solution to Dynamic Repeated Consensus for Blockchains. In 4th International Symposium on Foundations and Applications of Blockchain 2021 (FAB 2021). Open Access Series in Informatics (OASIcs), Volume 92, pp. 1:1-1:23, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2021)

Copy BibTex To Clipboard

@InProceedings{astefanoaei_et_al:OASIcs.FAB.2021.1,
  author =	{A\c{s}tef\u{a}noaei, L\u{a}cr\u{a}mioara and Chambart, Pierre and Del Pozzo, Antonella and Rieutord, Thibault and Tucci-Piergiovanni, Sara and Z\u{a}linescu, Eugen},
  title =	{{Tenderbake - A Solution to Dynamic Repeated Consensus for Blockchains}},
  booktitle =	{4th International Symposium on Foundations and Applications of Blockchain 2021 (FAB 2021)},
  pages =	{1:1--1:23},
  series =	{Open Access Series in Informatics (OASIcs)},
  ISBN =	{978-3-95977-196-2},
  ISSN =	{2190-6807},
  year =	{2021},
  volume =	{92},
  editor =	{Gramoli, Vincent and Sadoghi, Mohammad},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/OASIcs.FAB.2021.1},
  URN =		{urn:nbn:de:0030-drops-139877},
  doi =		{10.4230/OASIcs.FAB.2021.1},
  annote =	{Keywords: Blockchain, BFT-Consensus, Dynamic Repeated Consensus}
}
Document
DOI: 10.4230/LIPIcs.FSTTCS.2015.590
Failure-aware Runtime Verification of Distributed Systems

Authors: David Basin, Felix Klaedtke, and Eugen Zalinescu

Published in: LIPIcs, Volume 45, 35th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2015)

Abstract
Prior runtime-verification approaches for distributed systems are limited as they do not account for network failures and they assume that system messages are received in the order they are sent. To overcome these limitations, we present an online algorithm for verifying observed system behavior at runtime with respect to specifications written in the real-time logic MTL that efficiently handles out-of-order message deliveries and operates in the presence of failures. Our algorithm uses a three-valued semantics for MTL, where the third truth value models knowledge gaps, and it resolves knowledge gaps as it propagates Boolean values through the formula structure. We establish the algorithm's soundness and provide completeness guarantees. We also show that it supports distributed system monitoring, where multiple monitors cooperate and exchange their observations and conclusions.
Cite as

David Basin, Felix Klaedtke, and Eugen Zalinescu. Failure-aware Runtime Verification of Distributed Systems. In 35th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2015). Leibniz International Proceedings in Informatics (LIPIcs), Volume 45, pp. 590-603, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2015)

Copy BibTex To Clipboard

@InProceedings{basin_et_al:LIPIcs.FSTTCS.2015.590,
  author =	{Basin, David and Klaedtke, Felix and Zalinescu, Eugen},
  title =	{{Failure-aware Runtime Verification of Distributed Systems}},
  booktitle =	{35th IARCS Annual Conference on Foundations of Software Technology and Theoretical Computer Science (FSTTCS 2015)},
  pages =	{590--603},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-939897-97-2},
  ISSN =	{1868-8969},
  year =	{2015},
  volume =	{45},
  editor =	{Harsha, Prahladh and Ramalingam, G.},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.FSTTCS.2015.590},
  URN =		{urn:nbn:de:0030-drops-56194},
  doi =		{10.4230/LIPIcs.FSTTCS.2015.590},
  annote =	{Keywords: Runtime verification, monitoring algorithm, real-time logics, multi-valued semantics, distributed systems, asynchronous communication}
}
Document
DOI: 10.4230/OASIcs.TrustworthySW.2006.691
Relating two standard notions of secrecy

Authors: Eugen Zalinescu, Véronique Cortier, and Michaël Rusinowitch

Published in: OASIcs, Volume 3, Workshop on Trustworthy Software (2006)

Abstract
Two styles of definitions are usually considered to express that a security protocol preserves the confidentiality of a data { t s}. Reach-ability-based secrecy means that { t s} should never be disclosed while equi-valence-based secrecy states that two executions of a protocol with distinct instances for { t s} should be indistinguishable to an attacker. Although the second formulation ensures a higher level of security and is closer to cryptographic notions of secrecy, decidability results and automatic tools have mainly focused on the first definition so far. This paper initiates a systematic investigation of situations where syntactic secrecy entails strong secrecy. We show that in the passive case, reachability-based secrecy actually implies equivalence-based secrecy for signatures, symmetric and asymmetric encryption provided that the primitives are probabilistic. For active adversaries in the case of symmetric encryption, we provide sufficient (and rather tight) conditions on the protocol for this implication to hold.
Cite as

Eugen Zalinescu, Véronique Cortier, and Michaël Rusinowitch. Relating two standard notions of secrecy. In Workshop on Trustworthy Software. Open Access Series in Informatics (OASIcs), Volume 3, pp. 1-29, Schloss Dagstuhl – Leibniz-Zentrum für Informatik (2006)

Copy BibTex To Clipboard

@InProceedings{zalinescu_et_al:OASIcs.TrustworthySW.2006.691,
  author =	{Zalinescu, Eugen and Cortier, V\'{e}ronique and Rusinowitch, Micha\"{e}l},
  title =	{{Relating two standard notions of secrecy}},
  booktitle =	{Workshop on Trustworthy Software},
  pages =	{1--29},
  series =	{Open Access Series in Informatics (OASIcs)},
  ISBN =	{978-3-939897-02-6},
  ISSN =	{2190-6807},
  year =	{2006},
  volume =	{3},
  editor =	{Autexier, Serge and Merz, Stephan and van der Torre, Leon and Wilhelm, Reinhard and Wolper, Pierre},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{https://drops.dagstuhl.de/entities/document/10.4230/OASIcs.TrustworthySW.2006.691},
  URN =		{urn:nbn:de:0030-drops-6911},
  doi =		{10.4230/OASIcs.TrustworthySW.2006.691},
  annote =	{Keywords: Verification, security protocols, secrecy, applied-pi calculus}
}
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