2023Activity reportProject-TeamPESTO

3.2.1 Generic proof techniques

Most automated tools for verifying security properties rely on techniques stemming from automated deduction. Often existing techniques do however not apply directly, or do not scale up due to state explosion problems. For instance, the use of Horn clause resolution techniques requires dedicated resolution methods 33, 37. Another example is unification modulo equational theory, which is a key technique in several tools, e.g. 46. Security protocols however require to consider particular equational theories that are not naturally studied in classical automated reasoning. Sometimes, even new concepts have been introduced. One example is the finite variant property  39, which is used in several tools, e.g., Akiss  37, Maude-NPA  46 and TAMARIN  52. Another example is the notion of asymmetric unification  45 which is a variant of unification used in Maude-NPA to perform important syntactic pruning techniques of the search space, even when reasoning modulo an equational theory. For each of these topics we need to design efficient decision procedures for a variety of equational theories.

3.2.2 Dedicated procedures and tools

We design dedicated techniques for automated protocol verification. While existing techniques for security protocol verification are efficient and have reached maturity for verification of confidentiality and authentication properties (or more generally safety properties), our goal is to go beyond these properties and the standard attacker models, verifying the properties and attacker models identified in Section 3.1. This includes techniques that:

• can analyse indistinguishability properties, including for instance anonymity and unlinkability properties, but also properties stated in simulation-based (also known as universally composable) frameworks, which express the security of a protocol as an ideal (correct by design) system;
• take into account protocols that rely on a notion of mutable global state which does not arise in traditional protocols, but is essential when verifying tamper-resistant hardware devices, e.g., the RSA PKCS#11 standard, IBM's CCA and the trusted platform module (TPM);
• consider attacker models for protocols relying on weak secrets that need to be copied or remembered by a human, such as multi-factor authentication.

These goals are beyond the scope of most current analysis tools and require both theoretical advances in the area of verification, as well as the design of new efficient verification tools.

3.3.1 General design techniques

Design techniques include composition results that allow one to design protocols in a modular way 40, 38. Composition results come in many flavours: they may allow one to compose protocols with different objectives, e.g. compose a key exchange protocol with a protocol that requires a shared key or rely on a protocol for secure channel establishment, compose different protocols in parallel that may re-use some key material, or compose different sessions of the same protocol.

Another area where composition is of particular importance is Service Oriented Computing, where an “orchestrator” must combine some available component services, while guaranteeing some security properties. In this context, we work on the automated synthesis of the orchestrator or monitors for enforcing the security goals. These problems require the study of new classes of automata that communicate with structured messages.

3.3.2 New protocol design

We also design new protocols. Application areas that seem of particular importance are:

• External hardware devices such as security APIs that allow for flexible key management, including key revocation, and their integration in security protocols. The security fiasco of the PKCS#11 standard 35, 42 witnesses the need for new protocols in this area.
• Election systems that provide strong security guarantees. We have been working (in collaboration with the Caramba team) on a prototype implementation of an e-voting system, Belenios.
• Mechanisms for publishing personal information (e.g. on social networks) in a controlled way.

7.1.1 Belenios

• Name:
  Belenios - Verifiable online voting system
• Keyword:
  E-voting
• Functional Description:

  Belenios is an open-source online voting system that provides vote confidentiality and verifiability. End-to-end verifiability relies on the fact that the ballot box is public (voters can check that their ballots have been received) and on the fact that the tally is publicly verifiable (anyone can recount the votes). Vote confidentiality relies on the encryption of the votes and the distribution of the decryption key (no one detains the secret key).

  Belenios supports various kind of elections. In the standard mode, Belenios supports simple elections where voters simply select one or more candidates. It also supports arbitrary counting functions at the cost of a slightly more complex tally procedure for the authorities. For example, Belenios supports Condorcet, STV, and Majority Judgement, where voters rank candidates and grade them.

  Belenios is available in several languages for the voters as well as the administrators of an election. More languages can be freely added by users.

• News of the Year:

  In 2023, our platform was used to run about 1500 elections, with about 175,000 registered voters and 55,000 ballots counted.

  Some of the improvements made during this year are invisible for users. This includes the use of elliptic curves instead of finite fields, as a base group where the discrete logarithm problem is supposed to be hard. The use of elliptic curve allows to decrease the size of ballots and improve time efficiency. Also, some modifications have been made, so that the server can handle larger elections. This was successfully tested, with a real election of more than 30,000 voters.

  Other changes are visible to users. A new election administration interface based on a REST API is now available for beta-testing to the users. Also, the voter's journey has been slightly simplified, without impact on security. Finally, the STV counting system for preferential voting is now fully supported.

• URL:
  https://­www.­belenios.­org/
• Contact:
  Stéphane Glondu
• Participants:
  Pierrick Gaudry, Stéphane Glondu, Véronique Cortier
• Partners:
  CNRS, Inria

7.1.2 Tamarin

• Name:
  Tamarin prover
• Keywords:
  Security, Verification
• Functional Description:
  The Tamarin prover is a security protocol verification tool that supports both falsification and unbounded verification of security protocols specified as multiset rewriting systems with respect to (temporal) first-order properties and a message theory that models Diffie-Hellman exponentiation, bilinear pairing, multisets, and exclusive-or (XOR), combined with a user-defined convergent rewriting theory. Its main advantages are its ability to handle stateful protocols and its interactive proof mode. Moreover, it has been extended to verify equivalence properties. The tool is developed jointly by the PESTO team, the Institute of Information Security at ETH Zurich, and CISPA. In a joint effort, the partners wrote and published a user manual in 2016, available from the Tamarin website.
• Release Contributions:
  (1) Support for natural numbers and subterm reasoning, (2) Internal tactics language, (3) Advanced Diffie-Hellman (subgroups) with additional neutral group element added to Diffie-Hellman builtin, (4) Global macros, (5) Improved warnings, (6) Improved graph visualization.
• News of the Year:

  Several interns worked on Tamarin and implemented multiple improvements concerning in particular the tool's error handling and graph visualization.

  An extension to Tamarin that allows to model imperfect cryptographic hash functions was also developed. In extensive case studies using this methodology, the extended tool rediscovers all attacks that were previously reported for several vulnerable protocols and discovers several new variants.

• URL:
  http://­tamarin-prover.­github.­io/
• Publications:
  hal-03767104, hal-02903620, hal-02358878, hal-03693843, hal-03795715
• Contact:
  Jannik Dreier
• Participants:
  Jannik Dreier, Elise Klein, Maiwenn Racouchot, Véronique Cortier, Steve Kremer, Charlie Jacomme
• Partners:
  CISPA Helmholtz Center for Information Security, ETHZ

7.1.3 Jasmin

• Name:
  Jasmin compiler and analyser
• Keywords:
  Cryptography, Static analysis, Compilers
• Functional Description:

  The Jasmin programming language smoothly combines high-level and low-level constructs, so as to support “assembly in the head” programming. Programmers can control many low-level details that are performance-critical: instruction selection and scheduling, what registers to spill and when, etc. The language also features high-level abstractions (variables, functions, arrays, loops, etc.) to structure the source code and make it more amenable to formal verification. The Jasmin compiler produces predictable assembly and ensures that the use of high-level abstractions incurs no run-time penalty.

  The semantics is formally defined to allow rigorous reasoning about program behaviors. The compiler is formally verified for correctness (the proof is machine-checked by the Coq proof assistant). This ensures that many properties can be proved on a source program and still apply to the corresponding assembly program: safety, termination, functional correctness…

  Jasmin programs can be automatically checked for safety and termination (using a trusted static analyzer). The Jasmin workbench leverages the EasyCrypt toolset for formal verification. Jasmin programs can be extracted to corresponding EasyCrypt programs to prove functional correctness, cryptographic security, or security against side-channel attacks (constant-time).

• Release Contributions:

  2023.06.0 is a major release of Jasmin. It contains a few noteworthy changes that follows. Local functions now use call and ret instructions. The ARMv7 (i.e., Cortex-M4) architecture is now experimentally supported. A few aspects of the safety checker can be finely controlled through annotations or command-line flags. Shift and rotation operators have a simpler semantics.

  As usual, it also brings in various fixes and improvements, such as bit rotation operators and automatic slicing of the input program.

• News of the Year:
  On June 2023, a major release (2023.06.0) has been published.
• URL:
  https://­github.­com/­jasmin-lang/­jasmin
• Publications:
  hal-04106448, hal-04218417, hal-03844366, hal-03430789, hal-03352062, hal-02404581, hal-02974993, hal-01649140
• Contact:
  Jean-Christophe Léchenet
• Participants:
  Gilles Barthe, Benjamin Grégoire, Adrien Koutsos, Vincent Laporte, Jean-Christophe Léchenet, Swarn Priya, Santiago Arranz Olmos
• Partners:
  The IMDEA Software Institute, Ecole Polytechnique, Universidade do Minho, Universidade do Porto, Max Planck Institute for Security and Privacy

7.1.4 tlspuffin

• Name:
  TLS Protocol Under FuzzINg
• Keywords:
  Fuzzing, Formal methods, Cryptographic protocol
• Functional Description:
  tlspuffin is a full-fledged and modular DY fuzzer implementation in Rust. DY Fuzzing is a novel approach to fuzzing cryptographic protocols. It is based on the idea of using formal Dolev-Yao (DY) models as domain-specific knowledge to guide the fuzzer and give it the ability to detect logical attacks in protocol implementations. tlspuffin revolves around three main layers and modules that are of independent interest. First, the protocol- and Program Under Test-agnostic DY fuzzer that we implemented in a standalone module puffin uses the main fuzzing loop of the modular, state-of-the art fuzzer LibAFL. It implements custom test cases using DY traces, mutations, and objective oracle. On top of puffin, we built protocol-dependent fuzzers. We currently support tlspuffin for TLS and the preliminary sshpuffin for SSH. Third, we connect PUTs such as OpenSSL, LibreSSL, and wolfSSL to the fuzzers.
• News of the Year:
  We responsibly disclosed four logical attacks-based vulnerabilities we found with tlspuffin that affected the WolfSSL TLS library: CVE-2022-42905 (critical severity), CVE-2022-42905 and CVE-2022-42905 (high severity), and CVE-2022-38153 (medium severity). wolfSSL is a lightweight implementation widely used by IoT and embedded devices, and is able to run on OSs and CPUs otherwise not supported. See the associated paper: https://eprint.iacr.org/2023/57
• URL:
  https://­github.­com/­tlspuffin/­tlspuffin
• Contact:
  Lucca Hirschi
• Participants:
  Max Ammann, Lucca Hirschi, Steve Kremer
• Partner:
  Trail of Bits

8.1.1 Foundations of Automated Verification: Semantics, Decidability and Complexity

Participants: Véronique Cortier, Steve Kremer, Raphaëlle Crubillé, Christophe Ringeissen, Laurent Vigneron.

Security properties of cryptographic protocols are typically expressed as reachability or equivalence properties. Secrecy and authentication are examples of reachability properties while privacy properties such as untraceability, vote secrecy, or anonymity are generally expressed as behavioral equivalence in a process algebra that models security protocols.

Cheval (Inria Paris), Crubillé and Kremer study probabilistic process equivalences for security protocols. Symbolic models are classically purely non-deterministic. Indeed, generating random keys and nonces, or using randomized cryptographic primitives (like any secure encryption scheme) is idealized in symbolic models, replacing random numbers that can be guessed with only a negligible probability with perfectly fresh values that cannot be guessed at all. This abstraction has been widely used and has shown its usefulness. Another source of randomness may however come from the control flow. Typically, protocols aiming at anonymity, such as the Dining Cryptographers protocol, require users to take one action or another probabilistically. In this work we propose an extension of the applied pi calculus with a probabilistic choice operator (${+}_p$) and corresponding process equivalences. We show that it is essential that schedulers in such a probabilistic calculus are randomized, as non-randomized schedulers lead to definitions that have undesirable properties. We for instance show that typical behavioral relations would not be transitive and point out a flaw in the main theorem of a previous framework  48 that chose non-randomized schedulers. Mixing non-determinism and probabilistic choices generally leads to unsatisfactory behavioral equivalences: as the non-deterministic choices can leak the probabilistic choices, the resulting equivalences is too strong, modeling unrealistic attacker capabilities. We therefore investigate two sub-classes of protocols. We first consider the class of protocols that do not make any probabilistic choices, but allow the attacker to do so. Even though the honest processes may be purely non-deterministic, as the attacker is probabilistic, the resulting may testing equivalence is strictly stronger. We show that for a bounded number of sessions may-testing with a probabilistic attacker coincides with purely possibilistic similarity. Second, we consider a class of simple processes, with a very limited non-determinism. For this class, we show that trace equivalence coincides with may-testing where attackers are sequential processes (no parallel, nor non-deterministic choice) 7.

In collaboration with Erbatur (UT Dallas, USA) and Marshall (Univ Mary Washington, USA), Ringeissen studies reasoners and solvers for equational theories used in protocol analysis. In 22, the same authors plus Dwyer Satterfield (Univ Mary Washington, USA) have identified a class of term rewrite systems including the subterm convergent ones where the deduction problem and the static equivalence problem can be decided in a uniform way just like in the particular subterm convergent case. This class includes many theories of practical interest for which both deduction and static equivalence were decided until now on an individual basis. Beyond the decision problems related to equational unification and (intruder) theories, Ringeissen is also working on SMT (Satisfiability Modulo Theories) solvers to model verification conditions. In collaboration with Sheng (Stanford U.), Zohar (Bar Ilan U.), Reynolds (U. of Iowa), Barrett (Stanford U.) and Tinelli (U. of Iowa), Ringeissen published a journal paper on improving polite combination in presence of stably infinite theories 8. Christophe Ringeissen and Laurent Vigneron are also working on the definition of decision procedures based on congruence closure that could combine several equational theories.

8.1.2 Improving Verification Tools

Participants: Véronique Cortier, Alexandre Debant, Jannik Dreier, Lucca Hirschi, Elise Klein, Steve Kremer.

8.1.3 Analysis of Deployed Protocols

Participants: Elise Klein, Steve Kremer, Maïwenn Racouchot, Dhekra Mahmoud.

8.1.4 DY fuzzing: Dolev-Yao model-guided Fuzzing of Cryptographic Protocols

Participants: Lucca Hirschi, Steve Kremer.

Critical and widely used cryptographic protocols have repeatedly been found to contain flaws in their design and their implementation. A prominent class of such vulnerabilities is logical attacks, i.e., attacks that solely exploit flawed protocol logic. Automated formal verification methods, based on the Dolev-Yao (DY) attacker, excel at finding such flaws, but operate only on abstract specification models. Fully automated verification of existing protocol implementations is today still out of reach. This leaves open whether widely used protocol implementations are secure. Unfortunately, this blind spot hides numerous attacks, notably recent logical attacks on widely used TLS implementations introduced by implementation bugs.

In collaboration with Max Ammann (former master student), Hirschi and Kremer propose a novel and effective technique that we call DY model-guided fuzzing, which precludes logical attacks against protocol implementations 10. The main idea is to consider as possible test cases the set of abstract DY executions of the DY attacker, and use a mutation-based fuzzer to explore this set. The DY fuzzer concretizes each abstract execution to test it on the program under test. This approach enables reasoning at a more structural and security-related level of messages (e.g., decrypt a message and re-encrypt it with a different key) as opposed to random bit-level modifications that are much less likely to produce relevant logical adversarial behaviors. We implement a full-fledged and modular DY protocol fuzzer, dubbed puffin. We demonstrate its effectiveness by fuzzing three popular TLS implementations, resulting in the discovery of four novel vulnerabilities in WolfSSL, a lightweight implementation widely used by IoT and embedded devices, and able to run on OSs and CPUs otherwise not supported. Each of them has been responsibly disclosed to and fixed by WolfSSL. They have also been filed as CVEs.

8.1.5 Security of Cryptographic Implementations

Participant: Vincent Laporte.

8.2.1 Design of E-Voting Protocols

Participants: Véronique Cortier, Alexandre Debant, Anselme Goetschmann, Lucca Hirschi, Léo Louistisserand, Florian Moser, Quentin Yang.

Quentin Yang, co-supervised by Cortier and Gaudry (project-team Caramba), has defended his PhD thesis 27. Florian Moser, co-supervised by Cortier and Debant, has started in June 2023 and has proposed 30 a protocol based on code-voting for the context of Switzerland. It guarantees vote secrecy even against a dishonest voting client and still guarantees cast-as-intended, individual and universal verifiability under the trust assumptions of the Swiss Chancellery. Moser is designing a model in ProVerif to support these claims. Léo Louistisserand , co-supervised by Cortier and Gaudry (project-team Caramba), has started in September 2023. He has designed a protocol for a postal voting, that achieves both verifiability and vote privacy.

8.2.2 Security analyses of E-Voting Protocols

Participants: Véronique Cortier, Alexandre Debant, Lucca Hirschi, Peter Roenne, Quentin Yang.

8.3.1 Studying Frauds in Crypto-assets

Participants: Abdessamad Imine, Wail Zellagui.

In a joint project between LORIA and BETA labs, Abdessamad Imine and Yamina Tadjeddine-Fourneyron (Pr in economics, UL) plan to explore fraud detection in crypto-assets. Based on peer-to-peer networks, crypto-assets are currently very popular and at the heart of several financial transactions/services such as foreign currency loans, crypto-asset exchanges, and international money transfers. The challenge is to design techniques to accurately assess whether crypto-asset fraud is due to a lack of regulation, vulnerabilities in IT infrastructure/protocols, or both. Such techniques will require a classification of fraud and security methods, through a bi-disciplinary collaboration, namely economics and computer science.

8.3.2 Privacy-Preserving Big Data Management

Participants: Abdessamad Imine, Ala Eddine Laouir.

With the increasing use of software services in daily life, the data collected by service providers is massive and sensitive. Although current big data analytics frameworks provide enormous data processing capacity, obtaining appropriate and private responses to large-scale queries quickly and without revealing sensitive information remains a challenging problem. It is clear that Approximate Query Processing (AQP) achieves faster execution with reasonable accuracy loss and Differential Privacy (DP) is popular for enforcing privacy by noising answers to queries. We have addressed the problem of combining AQP and DP in multidimensional data based on range queries. We have presented our private approximation system called DiApprox which takes into account online sampling to accelerate the execution of range queries and minimizes the noise to be injected into the samples and query results in order to preserve the data privacy. Through empirical evaluation, we have showed that DiApprox is able to approximate aggregation on large datasets over $\times 21$ times faster than exact execution, with high accuracy.

8.3.3 Efficient Management of Filtering Rules in Software-defined Networking

Participants: Michaël Rusinowitch, Wafik Zahwa.

In a joint project with the Resist project-team and the Numeryx company, Lahmadi (Resist) and Rusinowitch have developed algorithms to automatically distribute and compress filtering rules on a set of switches of limited capacity. Now they investigate with Zahwa a more adaptive and autonomous approach based on reinforcement learning, as well as heuristics, aiming an application to self-configurating firewalls 26.

10.1.1 Visits to international teams

10.2.1 Other european programs/initiatives

Participant: Steve Kremer.

• EUGAIN, COST Action, European Network For Gender Balance in Informatics, duration: 4 years, since 2020, participant and leader of Working Group 3 – From PhD to Professor: Steve Kremer

10.3.1 ANR

• ANR JCJC ProtoFuzz Cryptographic Protocol Logic Fuzz Testing, duration: January 2023 – December 2026, leader: Lucca Hirschi.

  State-of-the-art formal methods for the verification of cryptographic protocols provide no guarantee on implementations, which are the end products that must be secure. Testing, especially fuzzing, is usable by practitioners, operates on implementations and has been very successful at finding low-level flaws but is unable to capture logical flaws. Therefore, effective techniques to preclude logical flaws from protocol implementations are desperately lacking.

  To fill this gap, we will develop the foundations, the design, and the implementation of an innovative hybrid, synergetic framework combining symbolic verification and fuzzing. In particular, we will (i) devise a simple protocol language and model extractor that enable extracting formal models from lightly annotated implementations and then refining those models based on functional correctness counter-examples and (ii) develop a novel testing methodology, symbolic-model-guided fuzzing, that, assisted by symbolic verifiers, efficiently captures logical attacks. The former will leverage a novel hybrid framework where symbolic formal models and implementations are tied together and can animate each other via dual executions.

  This project's ambitions are to significantly advance fuzzing and to establish hybrid frameworks combining fuzzing and symbolic verification as a new research topic, as well as to attack and improve the security of real-world, high-profile cryptographic protocols.

• ANR Chaire IA ASAP Tools for automated, symbolic analysis of real-world cryptographic protocols, duration: September 2020 – August 2024, leader: Steve Kremer.

  The goal of this project is the development of efficient algorithms and tools for automated verification of cryptographic protocols, that are able to comprehensively analyse detailed models of real-world protocols building on techniques from automated reasoning. Automated reasoning is the subfield of AI whose goal is the design of algorithms that enable computers to reason automatically, and these techniques underlie almost all modern verification tools. Current analysis tools for cryptographic protocols do however not scale well, or require to (over)simplify models, when applied on real-world, deployed cryptographic protocols. We aim at overcoming these limitations: we therefore design new, dedicated algorithms, include these algorithms in verification tools, and use the resulting tools for the security analyses of real-world cryptographic protocols.

• ANR SEVERITAS Secure and Verifiable Test and Assessment System, duration: Mai 2021 – April 2025, local coordinator: Jannik Dreier, other partners: LIG/University Grenoble Alpes (coordinator France), SnT/University of Luxembourg (coordinator Luxembourg), LIMOS/Université Clermont Auvergne.

  SEVERITAS advances information socio-technical security for Electronic Test and Assessment Systems (e-TAS). These systems measure skills and performances in education and training. They improve management, reduce time-to-assessment, reach larger audiences, but they do not always provide security by design. This project recognizes that the security aspects for e-TAS are still mostly unexplored. We fill these gaps by studying current and other to-be-defined security properties. We develop automated tools to advance the formal verification of security and show how to validate e-TAS security rigorously. We develop new secure, transparent, verifiable and lawful e-TAS procedures and protocols. We also deploy novel run-time monitoring strategies to reduce frauds and study the user experience about processes to foster e-TAS usable security. Thanks to connections with players in the business of e-TAS, such as OASYS, this project will contribute to the development of secure e-TAS.

10.3.2 PEPR

• PEPR CyberSecurity - SVP Verification of Security Protocols. duration: July 2022 – July 2028, local coordinator: Véronique Cortier, other partners: SPICY - Irisa (coordinator), Prosecco - Inria Paris, INSPIRE - LMF/ Université Paris-Saclay, STAMP - Inria Sophia

  The SVP project aims at enabling the analysis of protocols (either already deployed or in the design phase) at the level of abstract specifications as well as implementations. The goal is to develop techniques and tools allowing the implementation of solutions whose security will not be questioned in a cyclic way. To achieve this challenge, building on the work already done in the community of formal methods for security protocol verification, we notably plan to take the following steps : (i) developing new functionalities in existing tools to allow the analysis of more and more complex protocols ; (ii) building bridges between the different existing proof techniques and associated tools in order to take advantage of the strengths of each of them ; (iii) validate the techniques and tools developed within this project on widely deployed protocols and on more recent, fast-growing applications, such as Internet voting.

11.1.1 Scientific events: organisation

11.1.2 Scientific events: selection

11.1.3 Journal

11.1.4 Invited talks

• Véronique Cortier.

  Unifying speaker at ETAPS 2023, Paris, France, April 22-27, 2023.

  Keynote speaker at ABZ 2023, Nancy, France, May 30 – June 2, 2023.

  Seminar at the Summer School on real-world crypto and privacy 2023, Vodice, Croatia, 5-9 June 2023.

  Invited speaker at EVoteID 2023, Luxembourg City, Luxembourg, 3-6 October 2023.

• Alexandre Debant. UK-SPS/FM-Sec seminar, remote, November 2022.

• Lucca Hirschi.

  Contributed talk at Real World Crypto Symposium, March 2023, Tokyo, France.

  Invited talk at GDR Sécurité annual workshop, July 2023, Paris, France.

  Invited talk at Apple Tech Talk, November 2023 (virtual).

• Vincent Laporte.

  Lecturer at the Summer School on Security Testing and Verification (ST&V), September 2023, Leuven, Belgium.

  Invited speaker at GdR Informatique Mathématique annual workshop (RAIM), November 2023, Nancy, France.

11.1.5 Leadership within the scientific community

• Véronique Cortier: vice-chair of ACM Special Interest Group on Logic and Computation (SigLog)
• Véronique Cortier: member of IFIP WG-1.7 Foundations of Security Analysis
• Véronique Cortier: member of the research council of ANSSI
• Véronique Cortier: member of the research council of ESIEE
• Jannik Dreier: Co-chair of the working group on formal methods for security (GT MFS) of the GdR Sécurité Informatique
• Steve Kremer: member of IFIP WG-1.7 Foundations of Security Analysis
• Steve Kremer: member of the scientific directorate of the International Computer Science Meeting Center Schloss Dagstuhl
• Steve Kremer: member of the Board of Directors of LIST (Luxembourg Institute of Science and Technology)
• Michaël Rusinowitch: member of the IFIP WG-11.14 Secure Engineering

11.1.6 Scientific expertise

• Véronique Cortier: member of the expert panel on Computer Science of the Research Foundation – Flanders (FWO)
• Véronique Cortier: jury member of the Lovelace-Babbage Académie des Sciences award
• Steve Kremer: jury member of the Gilles Kahn PhD award

11.2.1 Teaching

• Licence:

  J. Dreier, Introduction to Logic, 50 hours (ETD), TELECOM Nancy

  J. Dreier, Formal Language Theory, 34 hours (ETD), TELECOM Nancy

  J. Dreier, Awareness for Cybersecurity, 7.5 hours (ETD), TELECOM Nancy

  L. Hirschi, Introduction to Theoretical Computer Science (Logic, Languages, Automata), 32 hours (ETD), TELECOM Nancy

  V. Laporte, Introduction to Theoretical Computer Science (Logic, Languages, Automata), 2023, 64 hours (ETD), TELECOM Nancy

• Master:

  J. Dreier, Cryptography and Authentication, 30 hours (ETD), M1 Computer Science, TELECOM Nancy

  J. Dreier, Introduction to Cryptography, 37 hours (ETD), M1 Computer Science, TELECOM Nancy

  J. Dreier, Protocol Security and Verification, 45 hours (ETD), M2 Computer Science, TELECOM Nancy

  J. Dreier, Advanced Cryptography, 32 hours (ETD), M2 Computer Science, TELECOM Nancy

  A. Imine, Security for XML Documents, 12 hours (ETD), M1, Univ Lorraine

  L. Hirschi, Protocol Security Theory, 24 hours (ETD), M2 Computer science, Univ Lorraine

  L. Vigneron, Security of information systems, 24 hours (ETD), M2 MIAGE – Audit and Design of Information Systems, Univ Lorraine

11.2.2 Supervision

• PhD defended in 2023:

  Quentin Yang, Design of a cast-as-intended, verifiable, and coercion-resistant electronic voting protocol 27, June 26th 2023, Univ. Lorraine (V. Cortier and P. Gaudry (project-team Caramba))

• PhD in progress:

  Vincent Diemunsch, Formal Analysis of Industrial Protocols, started in June 2022. (L. Hirschi and S. Kremer)

  Tom Gouville, Fuzzing of Cryptographic Protocols, started in November 2023. (L. Hirschi and S. Kremer)

  Elise Klein, Automatic Synthesis of Cryptographic Protocols, started in October 2021. (J. Dreier and S. Kremer)

  Ala Eddine Laouir, Privacy-Preserving Big Data Management and Analytics in Distributed Environments, started in 2021. (A. Imine)

  Léo Louistisserand, Remote Voting Protocols, started in September 2023. (V. Cortier and P. Gaudry (project-team Caramba))

  Dhekra Mahmoud, Security of Electronic Exams, started in 2022. (P. Lafourcade (LIMOS, Univ Clermont Auvergne) and J. Dreier)

  Florian Moser, Provably Secure Internet Voting, started in July 2023. (A. Debant and V. Cortier)

  Maïwenn Racouchot, Automated Learning of Proof Strategies in Tamarin, started in October 2021. (J. Dreier and S. Kremer)

  Wafik Zahwa, Building Self-Driven Network Functions, started in October 2022. (A. Lahmadi (project-team Resist) and M. Rusinowitch)

  Wail Zellagui, started in November 2023. (A. Imine)

11.2.3 Juries

11.3.1 Articles and contents

• Article in The Conversation about e-voting and its induced risks, 2023 (A. Debant, L. Hirschi)

11.3.2 Interventions

• Book signing at the Assemblée Nationale for the book "Vote Électronique" published by Odile Jacob (V. Cortier, with P. Gaudry - Caramba team)

International journals

• 7 articleV.Vincent Cheval, R.Raphaëlle Crubillé and S.Steve Kremer. Symbolic protocol verification with dice: Process equivalences in the presence of probabilities.Journal of Computer SecurityJune 2023, 1-38HALDOIback to text
• 8 articleY.Ying Sheng, Y.Yoni Zohar, C.Christophe Ringeissen, A. J.Andrew J Reynolds, C.Clark Barrett and C.Cesare Tinelli. Combining Stable Infiniteness and (Strong) Politeness.Journal of Automated Reasoning6742023, 34HALDOIback to text

International peer-reviewed conferences

• 9 inproceedingsB.Basavesh Ammanaghatta Shivakumar, G.Gilles Barthe, B.Benjamin Grégoire, V.Vincent Laporte, T.Tiago Oliveira, S.Swarn Priya, P.Peter Schwabe and L.Lucas Tabary-Maujean. Typing High-Speed Cryptography against Spectre v1.2023 IEEE Symposium on Security and Privacy (SP)SP 2023- IEEE Symposium on Security and PrivacySan Francisco, United StatesMay 2023, 1592-1609HALDOIback to text
• 10 inproceedingsM.Max Ammann, L.Lucca Hirschi and S.Steve Kremer. DY Fuzzing: Formal Dolev-Yao Models Meet Cryptographic Protocol Fuzz Testing.45th IEEE Symposium on Security and Privacy45th IEEE Symposium on Security and PrivacySan Francisco (CA, USA), United States2024HALback to text
• 11 inproceedingsJ.José Bacelar Almeida, M.Manuel Barbosa, G.Gilles Barthe, B.Benjamin Grégoire, V.Vincent Laporte, J.-C.Jean-Christophe Léchenet, T.Tiago Oliveira, H.Hugo Pacheco, M.Miguel Quaresma, P.Peter Schwabe, A.Antoine Séré and P.-Y.Pierre-Yves Strub. Formally verifying Kyber: Episode IV: Implementation correctness.ACR Transactions on Cryptographic Hardware and Embedded SystemsCHES 2023 - Conference on Cryptographic Hardware and Embedded Systems20233Praha, Czech RepublicJune 2023, 164-193HALDOIback to text
• 12 inproceedingsD.David Baelde, A.Alexandre Debant and S.Stéphanie Delaune. Proving Unlinkability using ProVerif through Desynchronized Bi-Processes.36th IEEE Computer Security Foundations SymposiumIEEE Computer Security Foundations SymposiumDubrovnik, CroatiaJuly 2023HALback to text
• 13 inproceedingsV.Vincent Cheval, V.Véronique Cortier and A.Alexandre Debant. Election Verifiability with ProVerif.CSF 2023 - 36th IEEE Computer Security Foundations SymposiumDubrovnik, CroatiaJuly 2023HALback to text
• 14 inproceedingsV.Vincent Cheval, C.Cas Cremers, A.Alexander Dax, L.Lucca Hirschi, C.Charlie Jacomme and S.Steve Kremer. Hash Gone Bad: Automated discovery of protocol attacks that exploit hash function weaknesses.32nd USENIX Security SymposiumAnaheim, United States2023HALback to text
• 15 inproceedingsV.Véronique Cortier, A.Alexandre Debant, P.Pierrick Gaudry and S.Stéphane Glondu. Belenios with cast as intended.Voting 2023 - 8th Workshop on Advances in Secure Electronic VotingBol, Brač, CroatiaMay 2023HALback to text
• 16 inproceedingsV.Véronique Cortier, P.Pierrick Gaudry, S.Stéphane Glondu and S.Sylvain Ruhault. French 2022 legislatives elections: a verifiability experiment.Proceedings E-Vote-Id 2023The E-Vote-ID Conference 2023Luxembourg City, LuxembourgOctober 2023HALback to text
• 17 inproceedings V.Véronique Cortier, P.Pierrick Gaudry and Q.Quentin Yang. Is the JCJ voting system really coercion-resistant? 37th IEEE Computer Security Foundations Symposium (CSF) CSF 2024 Enschede, Netherlands IEEE 2024 HAL back to text
• 18 inproceedingsA.Alexandre Debant and L.Lucca Hirschi. Reversing, Breaking, and Fixing the French Legislative Election E-Voting Protocol.USENIX Security 2023Anaheim, United StatesAugust 2023HALback to text
• 19 inproceedings H.Henri Devillez, O.Olivier Pereira, T.Thomas Peters and Q.Quentin Yang. Can we cast a ballot as intended and be receipt free? IEEE Symposium on Security and Privacy 2024 San Francisco, United States May 2024 HAL back to text
• 20 inproceedingsC. C.Constantin Catalin Dragan, F.François Dupressoir, K.Kristian Gjøsteen, T.Thomas Haines, P.Peter Rønne and M. R.Morten Rotvold Solberg. Machine-Checked Proofs of Accountability: How to sElect who is to Blame.Computer Security - ESORICS 2023 - 28th European Symposium on Research in Computer Security, ProceedingsESORICS 2023The Hague, The Netherlands, NetherlandsSeptember 2023HAL
• 21 inproceedingsW.Wei Du, P.Paliath Narendran and M.Michael Rusinowitch. Inferring RPO Symbol Ordering.UNIF 2023 - Informal Proceedings of the 37th International Workshop on UnificationUNIF 2023 - 37th International Workshop on UnificationRome, ItalyJuly 2023HAL
• 22 inproceedingsS.Saraid Dwyer Satterfield, S.Serdar Erbatur, A. M.Andrew M. Marshall and C.Christophe Ringeissen. Knowledge Problems in Security Protocols: Going Beyond Subterm Convergent Theories.Leibniz International Proceedings in Informatics (LIPIcs)8th International Conference on Formal Structures for Computation and Deduction (FSCD 2023)260Leibniz International Proceedings in Informatics (LIPIcs)Rome, ItalyJune 2023, 30:1--30:19HALDOIback to text
• 23 inproceedingsC.Charlie Jacomme, E.Elise Klein, S.Steve Kremer and M.Maïwenn Racouchot. A comprehensive, formal and automated analysis of the EDHOC protocol.USENIX Security '23 - 32nd USENIX Security SymposiumAnaheim, CA, United StatesAugust 2023HALback to text
• 24 inproceedingsL.Ludovic Paillat, C.-L.Claudia-Lavinia Ignat, D.Davide Frey, M.Mathieu Turuani and A.Amine Ismail. Design of an Efficient Distributed Delivery Service for Group Key Agreement Protocols.Lecture Notes in Computer Science (LNCS)FPS 2023 - 16th International Symposium on Foundations & Practice of SecurityBordeaux, FranceDecember 2023, 1-16HAL
• 25 inproceedingsA.Anggrio Sutopo, T.Thomas Haines and P.Peter Rønne. On the Auditability of the Estonian IVXV System and an Attack on Individual Verifiability.Workshop on Advances in Secure Electronic VotingBol, brac, CroatiaMay 2023HALback to text
• 26 inproceedingsW.Wafik Zahwa, A.Abdelkader Lahmadi, M.Michael Rusinowitch and M.Mondher Ayadi. Automated Placement of In-Network ACL Rules.International Conference on Network Softwarization (NetSoft)2023 IEEE 9th International Conference on Network Softwarization (NetSoft)Madrid, SpainIEEEJune 2023, 486-491HALDOIback to text

Doctoral dissertations and habilitation theses

• 27 thesisQ.Quentin Yang. Résistance à la coercition en vote électronique : conception et analyse.Université de LorraineJune 2023HALback to textback to text

Reports & preprints

• 28 miscV.Vincent Cheval, R.Raphaëlle Crubillé and S.Steve Kremer. Symbolic protocol verification with dice: process equivalences in the presence of probabilities (extended version).May 2023HAL
• 29 miscA.Alexandre Debant and L.Lucca Hirschi. Reversing, Breaking, and Fixing the French Legislative Election E-Voting Protocol.December 2023HAL
• 30 reportF.Florian Moser. Short Voting Codes For Practical Code Voting.INRIA NancyNovember 2023HALback to text

Scientific popularization

• 31 inproceedingsL.Laurent Vigneron. AI for securing communications.Workshop sur l’Intelligence Artificielle et son impact dans les différentes organisationsLongwy, FranceJuly 2023HAL