Romaric LUDINARD

Poste

Maitre de conférences

Département

Département Systèmes Réseaux, Cybersécurité et Droit du numérique

Localisation

Rennes

Contact information:

Tél.

+33 2 99 12 24 03
Biographie

I am currently associate professor at IMT Atlantique. Before that, I was associate professor at ENSAI, the national school for Statistics and Information Analysis during two years. I was head of the Data scientist specialization, and head of the computer science team. Before that, I was research and teaching assistant at University of Rennes during one year.

My research mainly focuses on models, safety and performance of distributed systems. I felt in these fields just after having received my engineering degree in computer science from University of Rennes 1 in 2006. At this time, I have started working on fault tolerance in the specific field of intrusion detection systems in the context of DADDi project. Then, I worked on  byzantine fault tolerance in large scale distributed systems in the context of P2PIm@ges project. In 2010, I joined Supelec for one year to work on anomaly based intrusion detection systems in the context of DALI project. In 2011, I was funded by Inria and Technicolor to prepare my phD on fault characterization in large scale networks.

I am currently focusing my research on Blockchain protocols and their guarantees.

  • 2016/2017 --- Projet Exploratoire Premier Soutien "Sécurité Informatique et des Systèmes Cyberphysiques" (PEPS SISC) CNRS BIPs
  • Since 09/2015 --- Associate Professor at Ensai, Head of Data Scientist Specialization
  • 02/2015 - 08/2015 --- PostDoc at Research Center for Cyber Intelligence and Information Security, Université La Sapienza, Rome
  • 09/2014 - 08/2014 --- Researching and teaching assistant at Université Rennes 1
  • 05/2011 - 08/2014 --- PhD Student in Dionysos team
  • 04/2010 - 04/2011 --- Research engineer in Dali project
  • 11/2007 - 03/2010 --- Research engineer in P2PIm@ges project
  • 10/2006 - 09/2007 --- Research engineer in DADDi project
  • 2006 --- Internship at France Télécom R & D--- Implementation and simulation of p2p protocols
  • 2005 --- Internship at Inria--- Implementation and simulation of SAM : self-* atomic memory for P2P systems

Talks

  • Jun'17 : Panel debate on Blockchain at ESEO Video
  • Jun'17 : Presentation about Blockchain and distributed agreement protocols at BlockSem Seminar
  • May'17 : Presentation about the danger of blockchain forks and fork avoidance at Open Source Innovation Spring 2017
  • April'17 : Presentation blockchain conflict preventions at ACM SAC 2017
  • March'17 : Presentation on Blockchain based protocols safety at LS2N - Laboratoire des Sciences du Numérique de Nantes
  • March'17 : Presentation on Bitcoin and Blockchain at Institut d'Economie et de Management de Nantes - IAE
  • January'17 : Presentation of my work on Bitcoin and safety analysis of recent improvement proposals at RESCOM days
  • November'16 : Invited speaker at Blockchains day, organized by French Computer Science Society Talk
  • October'16 : Seminar on Bitcoin at Université La Sapienza, Rome
  • June 2016 : Presentation of my work on Blockchain improvement proposals and safety assessment at DSN'16
  • May 2016 : Presentation of my work on Blockchain improvement proposals and safety assessment at AlgoTel'16
  • June 2014 : Presentation of my work on fault characterization in large scale systems at DSN'14
  • May 2014 : Presentation of my work on fault characterization in large scale systems at AlgoTel'14
  • November 2013 : Presentation of my work on local fault characterization in large scale systems at Technicolor WOS 3
  • October 2013 : Presentation of my work on local fault characterization in large scale systems at SRDS'13
  • May 2013 : Presentation of my work application logic preserving DHT at AlgoTel'13
  • December 2012 : Presentation of my work application logic preserving DHT at Opodis'12
  • October 2012 : Presentation of my work on anomaly detection in web applications at CRISIS'12
  • June 2011 : Presentation of my work on anomaly detection in web applications at SSTIC'11
  • May 2011 : Presentation of my work on DHT resilience to eclipse attacks at CFIP'11
  • October 2008 : Presentation of my work on Byzantine tolerant DHT at SASO'08

Committees

  • TPC at SSTIC'12, '13, '14, NCA 2017
  • Reviewer at Elsevier Performance Evaluation
  • Subreviewer at NOTERE'12, PODC'15, SRDS'15, TRUSTCOM'15, AlgoTel'15, SRDS'16, NCA'16, DISC'17, ICDCN'18

Conference organization

2016 - 2017 ENSAI, 3è année, Systèmes distribués, 21h CM
ENSAI, 1ère année, Programmation orientée objet, 10,5h CM
ENSAI, 1ère année, Algorithmique et programmation, 4h30 TD / 19h30 TP

ENSAI, 1ère année, Atelier de modélisation et programmation objet, 18h TP
 

2015 - 2016 ENSAI, 3è année, Systèmes distribués, 21h CM
ENSAI, Msc Big Data, Parallelized systems, 18h CM
ENSAI, 1ère année, Algorithmique et programmation, 4h30 TD / 19h30 TP
ENSAI, 1ère année, Atelier de modélisation et programmation objet, 18h TP
 
2014 - 2015 Université Rennes 1, Licence 1, Algorithmique fonctionnelle, 20h TD / 20h TP
Université Rennes 1, Licence 2, Mathématiques pour l'informatique, 36h TD
Université Rennes 1 / ISTIC, Licence 3, Algorithmique des graphes, 20h TD
Université Rennes 1 / ISTIC, Licence 3, Algorithmique et programmation, 34h Cours-TD, 22h TP
Université Rennes 1 / ISTIC, Master 1, Atelier de conception objet, 56h Projet
Université Rennes 1, Licence 1, Bureautique et préparation au C2I, 20h TP
Université Rennes 1 / ISTIC, Mises à niveau en informatique, 12h TP
 
2013 - 2014 ENSAI, 1ère année, Programmation orientée objet, 27h TP
Publications HAL
Pré-publication, Document de travail
Anceaume Emmanuelle, Guellier Antoine, Ludinard Romaric
UTXOs as a proof of membership for Byzantine Agreement based Cryptocurrencies
2018
Bibtext :
@unpublished{anceaume:hal-01768190,
TITLE = {{UTXOs as a proof of membership for Byzantine Agreement based Cryptocurrencies}},
AUTHOR = {Anceaume, Emmanuelle and Guellier, Antoine and Ludinard, Romaric},
URL = {https://hal.archives-ouvertes.fr/hal-01768190},
NOTE = {working paper or preprint},
YEAR = {2018},
MONTH = Apr,
PDF = {https://hal.archives-ouvertes.fr/hal-01768190/file/UTXO.pdf},
HAL_ID = {hal-01768190},
HAL_VERSION = {v1},
}
Endnote :
%0 Unpublished work
%T UTXOs as a proof of membership for Byzantine Agreement based Cryptocurrencies
%+ Confidentialité, Intégrité, Disponibilité et Répartition (CIDRE)
%+ IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique)
%A Anceaume, Emmanuelle
%A Guellier, Antoine
%A Ludinard, Romaric
%8 2018-04-17
%D 2018
%Z Computer Science [cs]
%Z Computer Science [cs]/Data Structures and Algorithms [cs.DS]
%Z Computer Science [cs]/Distributed, Parallel, and Cluster Computing [cs.DC]Preprints, Working Papers, ...
%X The presence of forks in permissionless blockchains is a recurrent issue. So far this has been handled either a posteriori, through local arbitration rules (e.g., " keep the branch which has required the most computational power ") which are applied once a fork is present in the blockchain, or a priori, via a Byzantine resilient agreement protocol periodically invoked by a committee of well identified and online nodes. In the former case, local arbitration rules guarantee that if they are correctly applied by a majority of the users of the system, then with high probability forks are progressively resolved, while in latter case, the sequence of Byzantine resilient agreements decide on the unique sequence of blocks to be appended to the blockchain. The question we may legitimately ask is the following one: To prevent the period of uncertainty inherent to optimistic-based solutions, are we doomed to rely on the decisions made by a unique committee whose members are already actively involved in the creation of blocs ? We negatively answer this question by presenting a solution that combines the best features of optimistic and pessimistic approaches: we leverage the presence of users and the " public-key as identities " principle to make users self-organize in small Byzantine resilient committees " around " each new object (i.e., blocks and transactions) to decide on their validity. Once validated, objects can be pushed in the network, appended to the blockchain without fearing any fork nor double spending attacks: we guarantee a " 0 "-confirmation delay. Additionally, our solution mitigates selfish attacks. We are not aware of any solutions enjoying such features.
%G English
%2 https://hal.archives-ouvertes.fr/hal-01768190/document
%2 https://hal.archives-ouvertes.fr/hal-01768190/file/UTXO.pdf
%L hal-01768190
%U https://hal.archives-ouvertes.fr/hal-01768190
%~ CENTRALESUPELEC
%~ SUP_CIDRE
%~ UNIV-PARIS-SACLAY
%~ CNRS
%~ UNIV-UBS
%~ INRIA-RENNES
%~ IRISA_SET
%~ CENTRALESUPELEC-SACLAY-VP
%~ UNIV-RENNES1
%~ INRIA_TEST
%~ CENTRALESUPELEC-SACLAY
%~ IRISA
%~ INRIA
%~ TEST-UR-CSS
%~ UNIV-RENNES
%~ INRIA-RENGRE
%~ UR1-HAL
%~ UR1-MATH-STIC
%~ UR1-UFR-ISTIC
Rapport
Anceaume Emmanuelle, Pozzo Antonella Del, Ludinard Romaric, Potop-Butucaru Maria, Tucci-Piergiovanni Sara
Blockchain Abstract Data Type
[Research Report] Sorbonne Université, CNRS, Laboratoire d'Informatique de Paris 6, LIP6, Paris, France. 2018, pp.1-30
Bibtext :
@techreport{anceaume:hal-01718480,
TITLE = {{Blockchain Abstract Data Type}},
AUTHOR = {Anceaume, Emmanuelle and Pozzo, Antonella Del and Ludinard, Romaric and Potop-Butucaru, Maria and Tucci-Piergiovanni, Sara},
URL = {https://hal.sorbonne-universite.fr/hal-01718480},
TYPE = {Research Report},
PAGES = {1-30},
INSTITUTION = {{Sorbonne Universit{\'e}, CNRS, Laboratoire d'Informatique de Paris 6, LIP6, Paris, France}},
YEAR = {2018},
MONTH = Feb,
KEYWORDS = { abstract data type ; blockchain ; consistency criteria},
PDF = {https://hal.sorbonne-universite.fr/hal-01718480/file/main.pdf},
HAL_ID = {hal-01718480},
HAL_VERSION = {v2},
}
Endnote :
%0 Report
%T Blockchain Abstract Data Type
%+ Confidentialité, Intégrité, Disponibilité et Répartition (CIDRE)
%+ Laboratoire d'Intégration des Systèmes et des Technologies (LIST)
%+ IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique)
%+ Advanced technologies for operated networks (ADOPNET)
%+ Laboratory of Information, Network and Communication Sciences (LINCS)
%+ Networks and Performance Analysis (NPA)
%A Anceaume, Emmanuelle
%A Pozzo, Antonella Del
%A Ludinard, Romaric
%A Potop-Butucaru, Maria
%A Tucci-Piergiovanni, Sara
%P 1-30
%I Sorbonne Université, CNRS, Laboratoire d'Informatique de Paris 6, LIP6, Paris, France
%8 2018-02-18
%D 2018
%Z 1802.09877
%K abstract data type
%K blockchain
%K consistency criteria
%Z Computer Science [cs]/Distributed, Parallel, and Cluster Computing [cs.DC]Reports
%X The presented work continues the line of recent distributed computing communityefforts dedicated to the theoretical aspects of blockchains. This paper is the rst tospecify blockchains as a composition of abstract data types all together with a hierarchyof consistency criteria that formally characterizes the histories admissible for distributedprograms that use them. Our work is based on an original oracle-based constructionthat, along with new consistency deffnitions, captures the eventual convergence processin blockchain systems. The paper presents as well some results on implementability ofthe presented abstractions and a mapping of representative existing blockchains fromboth academia and industry in our framework.
%G English
%2 https://hal.sorbonne-universite.fr/hal-01718480v2/document
%2 https://hal.sorbonne-universite.fr/hal-01718480/file/main.pdf
%L hal-01718480
%U https://hal.sorbonne-universite.fr/hal-01718480
%~ UPMC
%~ CNRS
%~ UNIV-UBS
%~ INRIA-RENNES
%~ INSTITUT-TELECOM
%~ IRISA_SET
%~ UNIV-RENNES1
%~ CEA
%~ INRIA_TEST
%~ CEA-UPSAY
%~ DRT
%~ UR1-HAL
%~ LARA
%~ CENTRALESUPELEC
%~ CEA-UPSAY-SACLAY
%~ IRISA
%~ LIP6
%~ INRIA
%~ SUP_CIDRE
%~ LIST
%~ TEST-UR-CSS
%~ UNIV-RENNES
%~ INRIA-RENGRE
%~ UR1-MATH-STIC
%~ CENTRALESUPELEC-SACLAY-VP
%~ UNIV-PARIS-SACLAY
%~ UR1-UFR-ISTIC
%~ CENTRALESUPELEC-SACLAY
%~ UPMC_POLE_1
Communication dans un congrès
Anceaume Emmanuelle, Ludinard Romaric, Potop-Butucaru Maria, Tronel Frédéric
Bitcoin a Distributed Shared Register
SSS 2017 - 19th International Symposium on Stabilization, Safety, and Security of Distributed Systems, Nov 2017, Boston, MA, United States. Springer, Proceedings of the 19th International Symposium on Stabilization, Safety, and Security of Distributed Systems, 10616, pp.456-468, 2017, Lecture Notes in Computer Science. 〈10.1007/978-3-319-69084-1_34〉
Bibtext :
@inproceedings{anceaume:hal-01522360,
TITLE = {{Bitcoin a Distributed Shared Register}},
AUTHOR = {Anceaume, Emmanuelle and Ludinard, Romaric and Potop-Butucaru, Maria and Tronel, Fr{\'e}d{\'e}ric},
URL = {https://hal.archives-ouvertes.fr/hal-01522360},
BOOKTITLE = {{SSS 2017 - 19th International Symposium on Stabilization, Safety, and Security of Distributed Systems}},
ADDRESS = {Boston, MA, United States},
PUBLISHER = {{Springer}},
SERIES = {Lecture Notes in Computer Science},
VOLUME = {10616},
PAGES = {456-468},
YEAR = {2017},
MONTH = Nov,
DOI = {10.1007/978-3-319-69084-1\_34},
KEYWORDS = {bitcoin ; formalization ; register ; regularity},
PDF = {https://hal.archives-ouvertes.fr/hal-01522360/file/sss.pdf},
HAL_ID = {hal-01522360},
HAL_VERSION = {v2},
}
Endnote :
%0 Conference Proceedings
%T Bitcoin a Distributed Shared Register
%+ Confidentialité, Intégrité, Disponibilité et Répartition (CIDRE)
%+ Ecole Nationale de la Statistique et de l'Analyse de l'Information [Bruz] (ENSAI)
%+ Sorbonne Universités
%+ Networks and Performance Analysis (NPA)
%A Anceaume, Emmanuelle
%A Ludinard, Romaric
%A Potop-Butucaru, Maria
%A Tronel, Frédéric
%< avec comité de lecture
%( Proceedings of the 19th International Symposium on Stabilization, Safety, and Security of Distributed Systems
%B SSS 2017 - 19th International Symposium on Stabilization, Safety, and Security of Distributed Systems
%C Boston, MA, United States
%I Springer
%3 Lecture Notes in Computer Science
%V 10616
%P 456-468
%8 2017-11-05
%D 2017
%R 10.1007/978-3-319-69084-1_34
%K bitcoin
%K formalization
%K register
%K regularity
%Z Computer Science [cs]
%Z Computer Science [cs]/Data Structures and Algorithms [cs.DS]
%Z Computer Science [cs]/Distributed, Parallel, and Cluster Computing [cs.DC]Conference papers
%X Distributed Ledgers (e.g. Bitcoin) occupy currently the first lines of the economical and political media and many speculations are done with respect to their level of coherence and their computability power. Interestingly, there is no consensus on the properties and abstractions that fully capture the behaviour of distributed ledgers. The interest in formalising the behaviour of distributed ledgers is twofold. Firstly, it helps to prove the correctness of the algorithms that implement existing distributed ledgers and explore their limits with respect to an unfriendly environment and target applications.%Secondly, it facilitates the identification of the minimal building blocks necessary to implement the distributed ledger in a specific environment. Even though the behaviour of distributed ledgers is similar to abstractions that have been deeply studied for decades in distributed systems no abstraction is sufficiently powerful to capture the distributed ledger behaviour.This paper introduces the Distributed Ledger Register, a register that mimics the behaviour of one of the most popular distributed ledger, i.e. the Bitcoin ledger. The aim of our work is to provide formal guarantees on the coherent evolution of Bitcoin. We furthermore show that the Bitcoin blockchain maintenance algorithm verifies the distributed ledger register properties under strict conditions. Moreover, we prove that the Distributed Ledger Register verifies the regularity register specification. It follows that the strongest coherency implemented by Bitcoin is regularity under strong assumptions (i.e. partial synchronous systems and sparse reads). This study contradicts the common belief that Bitcoin implements strong coherency criteria in a totally asynchronous system. To the best of our knowledge, our work is the first one that makes the connection between the distributed ledgers and the classical theory of distributed shared registers.
%G English
%2 https://hal.archives-ouvertes.fr/hal-01522360v2/document
%2 https://hal.archives-ouvertes.fr/hal-01522360/file/sss.pdf
%L hal-01522360
%U https://hal.archives-ouvertes.fr/hal-01522360
%~ CNRS
%~ UNIV-UBS
%~ IRISA_SET
%~ GENES
%~ UNIV-RENNES1
%~ INRIA_TEST
%~ SUP_CIDRE
%~ IRISA
%~ LIP6
%~ UPMC
%~ INRIA2017
%~ INRIA
%~ UR1-HAL
%~ UR1-MATH-STIC
%~ UR1-UFR-ISTIC
%~ CENTRALESUPELEC-SACLAY
%~ UPMC_POLE_1
%~ UNIV-PARIS-SACLAY
%~ TEST-UNIV-RENNES
%~ TEST-UR-CSS
%~ CENTRALESUPELEC-SACLAY-VP
%~ UNIV-RENNES
%~ INRIA-RENNES
%~ INRIA-RENGRE
%~ CENTRALESUPELEC
Communication dans un congrès
Lajoie-Mazenc Thibaut, Ludinard Romaric, Anceaume Emmanuelle
Handling Bitcoin Conflicts Through a Glimpse of Structure
Proceedings of the 32nd ACM SIGAPP Symposium On Applied Computing, Apr 2017, Marrakesh, Morocco. Proceedings of the 32nd ACM SIGAPP Symposium On Applied Computing. 〈10.1145/3019612.3019657〉
Bibtext :
@inproceedings{lajoiemazenc:hal-01634368,
TITLE = {{Handling Bitcoin Conflicts Through a Glimpse of Structure}},
AUTHOR = {Lajoie-Mazenc, Thibaut and Ludinard, Romaric and Anceaume, Emmanuelle},
URL = {https://hal.archives-ouvertes.fr/hal-01634368},
BOOKTITLE = {{Proceedings of the 32nd ACM SIGAPP Symposium On Applied Computing}},
ADDRESS = {Marrakesh, Morocco},
SERIES = {Proceedings of the 32nd ACM SIGAPP Symposium On Applied Computing},
YEAR = {2017},
MONTH = Apr,
DOI = {10.1145/3019612.3019657},
KEYWORDS = {Blockchain fork ; Design and analysis of algorithms ; Safety ; Bitcoin ; Double-spending attack ; Theory of computation $\rightarrow$ Probabilistic computation},
PDF = {https://hal.archives-ouvertes.fr/hal-01634368/file/camera-ready-version.pdf},
HAL_ID = {hal-01634368},
HAL_VERSION = {v1},
}
Endnote :
%0 Conference Proceedings
%T Handling Bitcoin Conflicts Through a Glimpse of Structure
%+ Confidentialité, Intégrité, Disponibilité et Répartition (CIDRE)
%+ Ecole Nationale de la Statistique et de l'Analyse de l'Information [Bruz] (ENSAI)
%A Lajoie-Mazenc, Thibaut
%A Ludinard, Romaric
%A Anceaume, Emmanuelle
%< avec comité de lecture
%B Proceedings of the 32nd ACM SIGAPP Symposium On Applied Computing
%C Marrakesh, Morocco
%3 Proceedings of the 32nd ACM SIGAPP Symposium On Applied Computing
%8 2017-04-04
%D 2017
%R 10.1145/3019612.3019657
%K Blockchain fork
%K Design and analysis of algorithms
%K Safety
%K Bitcoin
%K Double-spending attack
%K Theory of computation → Probabilistic computation
%Z Computer Science [cs]
%Z Computer Science [cs]/Data Structures and Algorithms [cs.DS]
%Z Computer Science [cs]/Distributed, Parallel, and Cluster Computing [cs.DC]Conference papers
%X Double spending and blockchain forks are two main issues that the Bitcoin crypto-system is confronted with. The former refers to an adversary's ability to use the very same coin more than once while the latter reflects the occurrence of transient inconsistencies in the history of the blockchain distributed data structure. We present a new approach to tackle these issues: it consists in adding some local synchronization constraints on Bitcoin's validation operations, and in making these constraints independent from the native blockchain protocol. Synchronization constraints are handled by nodes which are randomly and dynamically chosen in the Bitcoin system. We show that with such an approach, content of the blockchain is consistent with all validated transactions and blocks which guarantees the absence of both double-spending attacks and blockchain forks.
%G English
%2 https://hal.archives-ouvertes.fr/hal-01634368/document
%2 https://hal.archives-ouvertes.fr/hal-01634368/file/camera-ready-version.pdf
%L hal-01634368
%U https://hal.archives-ouvertes.fr/hal-01634368
%~ CNRS
%~ UNIV-UBS
%~ IRISA_SET
%~ GENES
%~ UNIV-RENNES1
%~ INRIA_TEST
%~ INRIA
%~ IRISA
%~ INRIA2017
%~ SUP_CIDRE
%~ UR1-HAL
%~ UR1-MATH-STIC
%~ UR1-UFR-ISTIC
%~ CENTRALESUPELEC-SACLAY
%~ UNIV-PARIS-SACLAY
%~ TEST-UNIV-RENNES
%~ TEST-UR-CSS
%~ CENTRALESUPELEC-SACLAY-VP
%~ UNIV-RENNES
%~ INRIA-RENNES
%~ INRIA-RENGRE
%~ CENTRALESUPELEC
Communication dans un congrès
Anceaume Emmanuelle, Lajoie-Mazenc Thibaut, Ludinard Romaric, Sericola Bruno
Safety Analysis of Bitcoin Improvement Proposals
IEEE Symposium on Network Computing and Applications, Oct 2016, Boston, United States
Bibtext :
@inproceedings{anceaume:hal-01397685,
TITLE = {{Safety Analysis of Bitcoin Improvement Proposals}},
AUTHOR = {Anceaume, Emmanuelle and Lajoie-Mazenc, Thibaut and Ludinard, Romaric and Sericola, Bruno},
URL = {https://hal.archives-ouvertes.fr/hal-01397685},
BOOKTITLE = {{IEEE Symposium on Network Computing and Applications}},
ADDRESS = {Boston, United States},
ORGANIZATION = {{IEEE}},
YEAR = {2016},
MONTH = Oct,
KEYWORDS = {Bitcoin ; Peer-to-Peer Systems ; Safety ; Ana- lytical Performance Evaluation},
PDF = {https://hal.archives-ouvertes.fr/hal-01397685/file/nca-bitcoin.pdf},
HAL_ID = {hal-01397685},
HAL_VERSION = {v1},
}
Endnote :
%0 Conference Proceedings
%T Safety Analysis of Bitcoin Improvement Proposals
%+ Confidentialité, Intégrité, Disponibilité et Répartition (CIDRE)
%+ Ecole Nationale de la Statistique et de l'Analyse de l'Information (ENSAI)
%+ Centre de Recherche en Économie et STatistique (CREST)
%+ Dependability Interoperability and perfOrmance aNalYsiS Of networkS (DIONYSOS)
%A Anceaume, Emmanuelle
%A Lajoie-Mazenc, Thibaut
%A Ludinard, Romaric
%A Sericola, Bruno
%< avec comité de lecture
%B IEEE Symposium on Network Computing and Applications
%C Boston, United States
%8 2016-10-31
%D 2016
%K Bitcoin
%K Peer-to-Peer Systems
%K Safety
%K Ana- lytical Performance Evaluation
%Z Computer Science [cs]
%Z Computer Science [cs]/Data Structures and Algorithms [cs.DS]
%Z Computer Science [cs]/Distributed, Parallel, and Cluster Computing [cs.DC]Conference papers
%X —Decentralized cryptocurrency systems offer a medium of exchange secured by cryptography, without the need of a centralized banking authority. Among others, Bitcoin is considered as the most mature one. Its popularity lies on the introduction of the concept of the blockchain, a public distributed ledger shared by all participants of the system. Double spending attacks and blockchain forks are two main issues in blockchain-based protocols. The first one refers to the ability of an adversary to use the very same bitcoin more than once, while blockchain forks cause transient inconsistencies in the blockchain. We show through probabilistic analysis that the reliability of recent solutions that exclusively rely on a particular type of Bitcoin actors, called miners, to guarantee the consistency of Bitcoin operations, drastically decreases with the size of the blockchain.
%G English
%2 https://hal.archives-ouvertes.fr/hal-01397685/document
%2 https://hal.archives-ouvertes.fr/hal-01397685/file/nca-bitcoin.pdf
%L hal-01397685
%U https://hal.archives-ouvertes.fr/hal-01397685
%~ CNRS
%~ UNIV-UBS
%~ INSTITUT-TELECOM
%~ IRISA_SET
%~ CREST
%~ ENSAI
%~ GENES
%~ UNIV-RENNES1
%~ INRIA
%~ IRISA
%~ INRIA_TEST
%~ INRIA2
%~ SUP_CIDRE
%~ PARISTECH
%~ UR1-HAL
%~ CENTRALESUPELEC
%~ UR1-MATH-STIC
%~ UR1-UFR-ISTIC
%~ CENTRALESUPELEC-SACLAY
%~ UNIV-PARIS-SACLAY
%~ TEST-UNIV-RENNES
%~ TEST-UR-CSS
%~ CENTRALESUPELEC-SACLAY-VP
%~ UNIV-RENNES
%~ INRIA-RENNES
%~ INRIA-RENGRE
Communication dans un congrès
Anceaume Emmanuelle, Ludinard Romaric, Sericola Bruno
Relying on Consensus does not Make Bitcoin Safer
Matthieu Roy; Javier Alonso Lopez; Antonio Casimiro. Fast Abstract in the 46th Annual IEEE/IFIP International Conference on Dependable Systems and Networks, Jun 2016, Toulouse, France. DSN2016-FAST-ABSTRACT
Bibtext :
@inproceedings{anceaume:hal-01316541,
TITLE = {{Relying on Consensus does not Make Bitcoin Safer}},
AUTHOR = {Anceaume, Emmanuelle and Ludinard, Romaric and Sericola, Bruno},
URL = {https://hal.archives-ouvertes.fr/hal-01316541},
BOOKTITLE = {{Fast Abstract in the 46th Annual IEEE/IFIP International Conference on Dependable Systems and Networks}},
ADDRESS = {Toulouse, France},
EDITOR = {Matthieu Roy and Javier Alonso Lopez and Antonio Casimiro},
SERIES = {DSN2016-FAST-ABSTRACT},
YEAR = {2016},
MONTH = Jun,
PDF = {https://hal.archives-ouvertes.fr/hal-01316541/file/Consensus%20does%20not%20Make%20Bitcoin%20Safer%20%281%29.pdf},
HAL_ID = {hal-01316541},
HAL_VERSION = {v1},
}
Endnote :
%0 Conference Paper
%F Oral
%T Relying on Consensus does not Make Bitcoin Safer
%+ Confidentialité, Intégrité, Disponibilité et Répartition (CIDRE)
%+ Dependability Interoperability and perfOrmance aNalYsiS Of networkS (DIONYSOS)
%A Anceaume, Emmanuelle
%A Ludinard, Romaric
%A Sericola, Bruno
%< avec comité de lecture
%B Fast Abstract in the 46th Annual IEEE/IFIP International Conference on Dependable Systems and Networks
%C Toulouse, France
%Y Matthieu Roy
%Y Javier Alonso Lopez
%Y Antonio Casimiro
%S DSN2016-FAST-ABSTRACT
%8 2016-06
%D 2016
%Z Computer Science [cs]/Distributed, Parallel, and Cluster Computing [cs.DC]Conference papers
%X Several distributed cryptocurrencies systems have emerged, and among them, Bitcoin is often designated as the pioneer this kind of systems. As such, Bitcoin shows some vulnerabil- ities in presence of malicious entities, and some recent works have proposed to improve upon Bitcoin weaknesses. This brief abstract is devoted to the analysis of one of these recent works, and shows through an analytical performance evaluation that new Bitcoin improvements are still needed.
%G English
%2 https://hal.archives-ouvertes.fr/hal-01316541/document
%2 https://hal.archives-ouvertes.fr/hal-01316541/file/Consensus%20does%20not%20Make%20Bitcoin%20Safer%20%281%29.pdf
%2 https://hal.archives-ouvertes.fr/hal-01316541/file/Consensus%20does%20not%20Make%20Bitcoin%20Safer.pdf
%L hal-01316541
%U https://hal.archives-ouvertes.fr/hal-01316541
%~ DSN2016-FAST-ABSTRACT
%~ CNRS
%~ UNIV-UBS
%~ INSTITUT-TELECOM
%~ IRISA_SET
%~ UNIV-RENNES1
%~ IRISA
%~ INRIA_TEST
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%~ INRIA
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%~ SUP_CIDRE
%~ UR1-MATH-STIC
%~ UR1-HAL
%~ UR1-UFR-ISTIC
%~ CENTRALESUPELEC-SACLAY
%~ UNIV-PARIS-SACLAY
%~ TEST-UNIV-RENNES
%~ TEST-UR-CSS
%~ CENTRALESUPELEC-SACLAY-VP
%~ UNIV-RENNES
%~ INRIA-RENNES
%~ INRIA-RENGRE
Communication dans un congrès
Anceaume Emmanuelle, Ludinard Romaric, Sericola Bruno
L'empire romain ne doit pas être géré comme une petite île grecque
ALGOTEL 2016 - 18èmes Rencontres Francophones sur les Aspects Algorithmiques des Télécommunications, May 2016, Bayonne, France. 〈http://algotel2016.labri.fr〉
Bibtext :
@inproceedings{anceaume:hal-01305334,
TITLE = {{L'empire romain ne doit pas {\^e}tre g{\'e}r{\'e} comme une petite {\^i}le grecque}},
AUTHOR = {Anceaume, Emmanuelle and Ludinard, Romaric and Sericola, Bruno},
URL = {https://hal.archives-ouvertes.fr/hal-01305334},
BOOKTITLE = {{ALGOTEL 2016 - 18{\`e}mes Rencontres Francophones sur les Aspects Algorithmiques des T{\'e}l{\'e}communications}},
ADDRESS = {Bayonne, France},
YEAR = {2016},
MONTH = May,
KEYWORDS = {Mots-clefs : Bitcoin ; Syst{\`e}me large {\'e}chelle ; Tol{\'e}rance aux fautes ; Analyse probabiliste},
PDF = {https://hal.archives-ouvertes.fr/hal-01305334/file/algotel2016-bitcoin.pdf},
HAL_ID = {hal-01305334},
HAL_VERSION = {v1},
}
Endnote :
%0 Conference Proceedings
%T L'empire romain ne doit pas être géré comme une petite île grecque
%+ Confidentialité, Intégrité, Disponibilité et Répartition (CIDRE)
%+ Centre de Recherche en Économie et STatistique (CREST)
%+ Ecole Nationale de la Statistique et de l'Analyse de l'Information (ENSAI)
%+ Dependability Interoperability and perfOrmance aNalYsiS Of networkS (DIONYSOS)
%A Anceaume, Emmanuelle
%A Ludinard, Romaric
%A Sericola, Bruno
%< avec comité de lecture
%B ALGOTEL 2016 - 18èmes Rencontres Francophones sur les Aspects Algorithmiques des Télécommunications
%C Bayonne, France
%8 2016-05-24
%D 2016
%K Mots-clefs : Bitcoin
%K Système large échelle
%K Tolérance aux fautes
%K Analyse probabiliste
%Z Computer Science [cs]/Networking and Internet Architecture [cs.NI]
%Z Computer Science [cs]/Performance [cs.PF]Conference papers
%X Depuis quelques années, des systèmes de crypto-devises ont fait leur apparition, permettant d'acheter des biens ou services de manière décentralisée en s'affranchissant de tout système bancaire. Bitcoin est un système pair-à-pair de crypto-devises considéré comme l'un des pionniers de ce type de système. Un adversaire peut chercher à mettre en dé-faut le système en insérant des données incohérentes dans l'historique des transactions, appelé blockchain. En exploitant une situation de compétition, il peut alors acquérir des biens ou services gratuitement. Afin de bloquer ces comporte-ments, PeerCensus propose d'utiliser des techniques d'accord basées sur les identités présentes dans la blockchain. Dans cet article, nous proposons une évaluation probabiliste de la fiabilité de l'architecture PeerCensus.
%G French
%2 https://hal.archives-ouvertes.fr/hal-01305334/document
%2 https://hal.archives-ouvertes.fr/hal-01305334/file/algotel2016-bitcoin.pdf
%L hal-01305334
%U https://hal.archives-ouvertes.fr/hal-01305334
%~ CNRS
%~ UNIV-UBS
%~ INSTITUT-TELECOM
%~ IRISA_SET
%~ UNIV-RENNES1
%~ IRISA
%~ INRIA_TEST
%~ INRIA2
%~ INRIA
%~ ALGOTEL2016
%~ SUP_CIDRE
%~ CENTRALESUPELEC
%~ CREST
%~ GENES
%~ ENSAI
%~ PARISTECH
%~ UR1-MATH-STIC
%~ UR1-HAL
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%~ CENTRALESUPELEC-SACLAY
%~ UNIV-PARIS-SACLAY
%~ TEST-UNIV-RENNES
%~ TEST-UR-CSS
%~ CENTRALESUPELEC-SACLAY-VP
%~ UNIV-RENNES
%~ INRIA-RENNES
%~ INRIA-RENGRE
Thèse
Ludinard Romaric
Caractérisation locale de fautes dans les systèmes large échelle
Réseaux et télécommunications [cs.NI]. Université Rennes 1, 2014. Français. 〈NNT : 2014REN1S065〉
Bibtext :
@phdthesis{ludinard:tel-01094191,
TITLE = {{Local fault characterization in large scale systems}},
AUTHOR = {Ludinard, Romaric},
URL = {https://hal.inria.fr/tel-01094191},
NUMBER = {2014REN1S065},
SCHOOL = {{Universit{\'e} Rennes 1}},
YEAR = {2014},
MONTH = Oct,
KEYWORDS = {ADistributed parameter systems ; Supervision ; Syst{\`e}mes distribu{\'e}s ; S{\^u}ret{\'e} de fonctionnement},
TYPE = {Theses},
PDF = {https://hal.inria.fr/tel-01094191/file/These_Ludinard.pdf},
HAL_ID = {tel-01094191},
HAL_VERSION = {v1},
}
Endnote :
%0 Thesis
%T Local fault characterization in large scale systems
%+ Dependability Interoperability and perfOrmance aNalYsiS Of networkS (DIONYSOS)
%A Ludinard, Romaric
%N 2014REN1S065
%I Université Rennes 1
%Y Bruno Sericola
%Y Emmanuelle Anceaume
%8 2014-10-02
%D 2014
%K ADistributed parameter systems
%K Supervision
%K Systèmes distribués
%K Sûreté de fonctionnement
%Z Computer Science [cs]/Networking and Internet Architecture [cs.NI]Theses
%X The Internet is a global system of interconnected computer networks that carries lots of services consumed by users. Unfortunately, each element this system may exhibit failures. A failure can be perceived by a variable range of users, according to the location of the failure source. This thesis proposes a set of contributions that aims at determining from a user perception if a failure is perceived by a few number of users (isolated failure) or in contrast by lots of them (massive failure). We formalize failures with respect to their impact on the services that are consumed by users. We show that it is impossible to determine with certainty if a user perceives a local or a massive failure, from the user point of view. Nevertheless, it is possible to determine for each user whether it perceives a local failure, a massive one or whether it is impossible to determine. This characterization is optimal and can be run in parallel. Then, we propose a self-Organizing architecture for fault characterization. Entities of the system organize themselves in a two-Layered overlay that allows to gather together entities with similar perception. This gathering allows us to successfully apply our characterization. Finally, a probabilistic evaluation of the resilience to dynamism and malicious behaviors of this architecture is performed.
%X Internet est un réseau de réseaux permettant la mise en œuvre de divers services consommés par les utilisateurs. Malheureusement, chacun des éléments présents dans le réseau ou impliqués dans ces services peut potentiellement exhiber des défaillances. Une défaillance peut être perçue par un nombre variable d'utilisateurs suivant la localisation dans le système de la source de celle-Ci. Cette thèse propose un ensemble de contributions visant à déterminer du point de vue d'un utilisateur percevant une défaillance, si celle-Ci est perçue par un faible nombre d'utilisateurs (défaillance isolée) ou à l'inverse par un très grand nombre d'utilisateurs (défaillance massive). Nous formalisons dans un premier temps les défaillances par leur impact sur la perception des services consommés par les utilisateurs. Nous montrons ainsi qu'il est impossible, du point de vue d'un utilisateur, de déterminer de manière certaine si une défaillance perçue est isolée ou massive. Cependant, il possible de déterminer de manière certaine pour chaque utilisateur, s'il a perçu une défaillance isolée, massive, ou s'il est impossible de le déterminer. Cette caractérisation est optimale et totalement parallélisable. Dans un second temps, nous proposons une architecture pour la caractérisation de fautes. Les entités du système s'organisent au sein d'une structure à deux niveaux permettant de regrouper ensemble les entités ayant des perceptions similaires et ainsi mener à bien l'approche proposée. Enfin, une analyse probabiliste de la résistance au dynamisme et aux comportements malveillants du second niveau de cette architecture complète ce document.
%G French
%2 https://hal.inria.fr/tel-01094191/document
%2 https://hal.inria.fr/tel-01094191/file/These_Ludinard.pdf
%L tel-01094191
%U https://hal.inria.fr/tel-01094191
%~ UNIV-RENNES1
%~ CNRS
%~ INRIA
%~ IRISA
%~ IRISA_SET
%~ IRISA-D2
%~ INRIA2
%~ UNIV-UBS
%~ INSTITUT-TELECOM
%~ INRIA_TEST
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%~ UR1-MATH-STIC
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%~ INRIA-RENGRE
Article dans une revue
Kermarrec Anne-Marie, Le Merrer Erwan, Le Scouarnec Nicolas, Ludinard Romaric, MaillÉ Patrick, Straub Gilles, Van Kempen Alexandre
Performance evaluation of a peer-to-peer backup system using buffering at the edge
Computer Communications, Elsevier, 2014, 52, pp.71 - 81. 〈10.1016/j.comcom.2014.06.002〉
Bibtext :
@article{kermarrec:hal-01185286,
TITLE = {{Performance evaluation of a peer-to-peer backup system using buffering at the edge}},
AUTHOR = {Kermarrec, Anne-Marie and Le Merrer, Erwan and Le Scouarnec, Nicolas and Ludinard, Romaric and MAILL{\'E}, Patrick and Straub, Gilles and Van Kempen, Alexandre},
URL = {https://hal.archives-ouvertes.fr/hal-01185286},
JOURNAL = {{Computer Communications}},
HAL_LOCAL_REFERENCE = {14904},
PUBLISHER = {{Elsevier}},
VOLUME = {52},
PAGES = {71 - 81},
YEAR = {2014},
MONTH = Oct,
DOI = {10.1016/j.comcom.2014.06.002},
KEYWORDS = {Peer-to-peer ; Availability ; Backup ; Storage},
PDF = {https://hal.archives-ouvertes.fr/hal-01185286/file/kermarrec2014performance.pdf},
HAL_ID = {hal-01185286},
HAL_VERSION = {v1},
}
Endnote :
%0 Journal Article
%T Performance evaluation of a peer-to-peer backup system using buffering at the edge
%+ As Scalable As Possible: foundations of large scale dynamic distributed systems (ASAP)
%+ Technicolor (Entreprise) (Technicolor)
%+ Confidentialité, Intégrité, Disponibilité et Répartition (CIDRE)
%+ Objets communicants pour l'Internet du futur (OCIF)
%+ Département Réseaux, Sécurité et Multimédia (RSM)
%A Kermarrec, Anne-Marie
%A Le Merrer, Erwan
%A Le Scouarnec, Nicolas
%A Ludinard, Romaric
%A MAILLÉ, Patrick
%A Straub, Gilles
%A Van Kempen, Alexandre
%< avec comité de lecture
%Z 14904
%@ 0140-3664
%J Computer Communications
%I Elsevier
%V 52
%P 71 - 81
%8 2014-10
%D 2014
%R 10.1016/j.comcom.2014.06.002
%K Peer-to-peer
%K Availability
%K Backup
%K Storage
%Z Computer Science [cs]/Networking and Internet Architecture [cs.NI]Journal articles
%X The availability of end devices of peer-to-peer storage and backup systems has been shown to be critical for usability and for system reliability in practice. This has led to the adoption of hybrid architectures composed of both peers and servers. Such architectures mask the instability of peers thus approaching the performances of client-server systems while providing scalability at a low cost. In this paper, we advocate the replacement of such servers by a cloud of residential gateways, as they are already present in users' homes, thus pushing the required stable components at the edge of the network. In our gateway-assisted system, gateways act as buffers between peers, compensating for their intrinsic instability. We model such a system, for quick dimensioning and estimation of gains. We then evaluate our proposal using statistical distributions based on real world traces, as well as a trace of residential gateways for availability (that we have collected and now make available). Results show that the time required to backup data in the network is substantially improved, as it drops from days to a few hours. As gateways are becoming increasingly powerful in order to enable new services, we expect such a proposal to be leveraged on a short term basis.
%G English
%2 https://hal.archives-ouvertes.fr/hal-01185286/document
%2 https://hal.archives-ouvertes.fr/hal-01185286/file/kermarrec2014performance.pdf
%L hal-01185286
%U https://hal.archives-ouvertes.fr/hal-01185286
%~ INSTITUT-TELECOM
%~ TELECOM-BRETAGNE
%~ CNRS
%~ UNIV-UBS
%~ UNIV-RENNES1
%~ IRISA_SET
%~ INRIA
%~ IRISA
%~ INRIA_TEST
%~ IRISA-D2
%~ IRISA-D1
%~ SUP_CIDRE
%~ CENTRALESUPELEC
%~ INRIA2
%~ UR1-HAL
%~ IRISA_TB
%~ UR1-MATH-STIC
%~ UR1-UFR-ISTIC
%~ TEST-UNIV-RENNES
%~ TEST-UR-CSS
%~ UNIV-RENNES
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%~ INRIA-RENGRE
%~ IMT-ATLANTIQUE
Article dans une revue
Ludinard Romaric, Totel Eric, Tronel Frédéric, Nicomette Vincent, Kaâniche Mohamed, Alata Eric, Akrout Rim, Bachy Yann
An Invariant-based Approach for Detecting Attacks against Data in Web Applications
Bibtext :
@article{ludinard:hal-01083296,
TITLE = {{An Invariant-based Approach for Detecting Attacks against Data in Web Applications}},
AUTHOR = {Ludinard, Romaric and Totel, Eric and Tronel, Fr{\'e}d{\'e}ric and Nicomette, Vincent and Ka{\^a}niche, Mohamed and Alata, Eric and Akrout, Rim and Bachy, Yann},
URL = {https://hal.inria.fr/hal-01083296},
JOURNAL = {{International Journal of Secure Software Engineering}},
VOLUME = {5},
NUMBER = {1},
PAGES = {19-38},
YEAR = {2014},
MONTH = Jun,
DOI = {10.4018/ijsse.2014010102},
KEYWORDS = {intrusion detection ; invariant discovery ; invariant checking ; web applications},
PDF = {https://hal.inria.fr/hal-01083296/file/IJSSE_APA4_def.pdf},
HAL_ID = {hal-01083296},
HAL_VERSION = {v1},
}
Endnote :
%0 Journal Article
%T An Invariant-based Approach for Detecting Attacks against Data in Web Applications
%+ Confidentialité, Intégrité, Disponibilité et Répartition (CIDRE)
%+ Équipe Tolérance aux fautes et Sûreté de Fonctionnement informatique (LAAS-TSF)
%A Ludinard, Romaric
%A Totel, Eric
%A Tronel, Frédéric
%A Nicomette, Vincent
%A Kaâniche, Mohamed
%A Alata, Eric
%A Akrout, Rim
%A Bachy, Yann
%Z Projet ANR DALI (Design and Assessment of application Level Intrusion detection systems).
%< avec comité de lecture
%J International Journal of Secure Software Engineering
%V 5
%N 1
%P 19-38
%8 2014-06-26
%D 2014
%R 10.4018/ijsse.2014010102
%K intrusion detection
%K invariant discovery
%K invariant checking
%K web applications
%Z Cognitive science/Computer scienceJournal articles
%X RRABIDS (Ruby on Rails Anomaly Based Intrusion Detection System) is an application levelintrusion detection system (IDS) for applications implemented with the Ruby on Railsframework. The goal of this intrusion detection system is to detect attacks against data in thecontext of web applications. This anomaly based IDS focuses on the modelling of the normalapplication profile using invariants. These invariants are discovered during a learning phase.Then, they are used to instrument the web application at source code level, so that a deviationfrom the normal profile can be detected at run-time. This paper illustrates on simple exampleshow the approach detects well-known categories of web attacks that involve a state violation ofthe application, such as SQL injections. Finally, an assessment phase is performed to evaluatethe accuracy of the detection provided by the proposed approach.
%G English
%2 https://hal.inria.fr/hal-01083296/document
%2 https://hal.inria.fr/hal-01083296/file/IJSSE_APA4_def.pdf
%L hal-01083296
%U https://hal.inria.fr/hal-01083296
%~ INSTITUT-TELECOM
%~ UNIV-RENNES1
%~ CNRS
%~ INRIA
%~ UNIV-UBS
%~ SUP_CIDRE
%~ IRISA-D1
%~ IRISA_SET
%~ IRISA
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%~ LAAS-INFORMATIQUE-CRITIQUE
%~ UR1-MATH-STIC
%~ INRIA_TEST
%~ INRIA2
%~ UR1-HAL
%~ INSA-TOULOUSE
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%~ TEST-UR-CSS
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%~ LAAS
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