Logical methods for the hierarchy of hyperlogics

In this thesis, we develop logical methods for reasoning about hyperproperties. Hyperproperties describe relations between multiple executions of a system. Unlike trace properties, hyperproperties comprise relational properties like noninterference, symmetry, and robustness. While trace properties have been studied extensively, hyperproperties form a relatively new concept that is far from fully understood. We study the expressiveness of various hyperlogics and develop algorithms for their satisfiability and synthesis problems. In the first part, we explore the landscape of hyperlogics based on temporal logics, first-order and second-order logics, and logics with team semantics. We establish that first-order/second-order and temporal hyperlogics span a hierarchy of expressiveness, whereas team logics constitute a radically different way of specifying hyperproperties. Furthermore, we introduce the notion of temporal safety and liveness, from which we obtain fragments of HyperLTL (the most prominent hyperlogic) with a simpler satisfiability problem. In the second part, we develop logics and algorithms for the synthesis of smart contracts. We introduce two extensions of temporal stream logic to express (hyper)properties of infinite-state systems. We study the realizability problem of these logics and define approximations of the problem in LTL and HyperLTL. Based on these approximations, we develop algorithms to construct smart contracts directly from their specifications.In dieser Arbeit beschreiben wir logische Methoden, um über Hypereigenschaften zu argumentieren. Hypereigenschaften beschreiben Relationen zwischen mehreren Ausführungen eines Systems. Anders als pfadbasierte Eigenschaften können Hypereigenschaften relationale Eigenschaften wie Symmetrie, Robustheit und die Abwesenheit von Informationsfluss ausdrücken. Während pfadbasierte Eigenschaften in den letzten Jahrzehnten ausführlich erforscht wurden, sind Hypereigenschaften ein relativ neues Konzept, das wir noch nicht vollständig verstehen. Wir untersuchen die Ausdrucksmächtigkeit verschiedener Hyperlogiken und entwickeln ausführbare Algorithmen, um deren Erfüllbarkeits- und Syntheseproblem zu lösen. Im ersten Teil erforschen wir die Landschaft der Hyperlogiken basierend auf temporalen Logiken, Logiken erster und zweiter Ordnung und Logiken mit Teamsemantik. Wir stellen fest, dass temporale Logiken und Logiken erster und zweiter Ordnung eine Hierarchie an Ausdrucksmächtigkeit aufspannen. Teamlogiken hingegen spezifieren Hypereigenschaften auf eine radikal andere Art. Wir führen außerdem das Konzept von temporalen Sicherheits- und Lebendigkeitseigenschaften ein, durch die Fragmente der bedeutensten Logik HyperLTL entstehen, für die das Erfüllbarkeitsproblem einfacher ist. Im zweiten Teil entwickeln wir Logiken und Algorithmen für die Synthese digitaler Verträge. Wir führen zwei Erweiterungen temporaler Stromlogik ein, um (Hyper)eigenschaften in unendlichen Systemen auszudrücken. Wir untersuchen das Realisierungsproblem dieser Logiken und definieren Approximationen des Problems in LTL und HyperLTL. Basierend auf diesen Approximationen entwickeln wir Algorithmen, die digitale Verträge direkt aus einer Spezifikation erstellen

Effective symbolic protocol analysis via equational irreducibility conditions

We address a problem that arises in cryptographic protocol analysis when the equational properties of the cryptosystem are taken into account: in many situations it is necessary to guarantee that certain terms generated during a state exploration are in normal form with respect to the equational theory. We give a tool-independent methodology for state exploration, based on unification and narrowing, that generates states that obey these irreducibility constraints, called contextual symbolic reachability analysis, prove its soundness and completeness, and describe its implementation in the Maude-NPA protocol analysis tool. Contextual symbolic reachability analysis also introduces a new type of unification mechanism, which we call asymmetric unification, in which any solution must leave the right side of the solution irreducible. We also present experiments showing the effectiveness of our methodology.S. Escobar and S. Santiago have been partially supported by the EU (FEDER) and the Spanish MEC/MICINN under grant TIN 2010-21062-C02-02, and by Generalitat Valenciana PROMETEO2011/052. The following authors have been partially supported by NSF: S. Escobar, J. Meseguer and R. Sasse under grants CCF 09- 05584, CNS 09-04749, and CNS 09-05584; D. Kapur under grant CNS 09-05222; C. Lynch, Z. Liu, and C. Meadows under grant CNS 09-05378, and P. Narendran and S. Erbatur under grant CNS 09-05286.Erbatur, S.; Escobar Román, S.; Kapur, D.; Liu, Z.; Lynch, C.; Meadows, C.; Meseguer, J.... (2012). Effective symbolic protocol analysis via equational irreducibility conditions. En Computer Security - ESORICS 2012. Springer Verlag (Germany). 7459:73-90. doi:10.1007/978-3-642-33167-1_5S73907459IEEE 802.11 Local and Metropolitan Area Networks: Wireless LAN Medium Access Control (MAC) and Physical (PHY) Specifications (1999)Abadi, M., Cortier, V.: Deciding knowledge in security protocols under equational theories. Theor. Comput. Sci. 367(1-2), 2–32 (2006)Arapinis, M., Bursuc, S., Ryan, M.: Privacy Supporting Cloud Computing: ConfiChair, a Case Study. In: Degano, P., Guttman, J.D. (eds.) Principles of Security and Trust. LNCS, vol. 7215, pp. 89–108. Springer, Heidelberg (2012)Basin, D., Mödersheim, S., Viganò, L.: An On-the-Fly Model-Checker for Security Protocol Analysis. In: Snekkenes, E., Gollmann, D. (eds.) ESORICS 2003. LNCS, vol. 2808, pp. 253–270. Springer, Heidelberg (2003)Baudet, M., Cortier, V., Delaune, S.: YAPA: A Generic Tool for Computing Intruder Knowledge. In: Treinen, R. (ed.) RTA 2009. LNCS, vol. 5595, pp. 148–163. Springer, Heidelberg (2009)Blanchet, B.: An efficient cryptographic protocol verifier based on prolog rules. In: CSFW, pp. 82–96. IEEE Computer Society (2001)Blanchet, B.: Using horn clauses for analyzing security protocols. In: Cortier, V., Kremer, S. (eds.) Formal Models and Techniques for Analyzing Security Protocols. IOS Press (2011)Blanchet, B., Abadi, M., Fournet, C.: Automated verification of selected equivalences for security protocols. J. Log. Algebr. Program. 75(1), 3–51 (2008)Ciobâcă, Ş., Delaune, S., Kremer, S.: Computing Knowledge in Security Protocols under Convergent Equational Theories. In: Schmidt, R.A. (ed.) CADE-22. LNCS (LNAI), vol. 5663, pp. 355–370. Springer, Heidelberg (2009)Comon-Lundh, H., Delaune, S.: The Finite Variant Property: How to Get Rid of Some Algebraic Properties. In: Giesl, J. (ed.) RTA 2005. LNCS, vol. 3467, pp. 294–307. Springer, Heidelberg (2005)Comon-Lundh, H., Delaune, S., Millen, J.: Constraint solving techniques and enriching the model with equational theories. In: Cortier, V., Kremer, S. (eds.) Formal Models and Techniques for Analyzing Security Protocols. Cryptology and Information Security Series, vol. 5, pp. 35–61. IOS Press (2011)Comon-Lundh, H., Shmatikov, V.: Intruder deductions, constraint solving and insecurity decision in presence of exclusive or. In: LICS, pp. 271–280. IEEE Computer Society (2003)Ciobâcă, Ş.: Knowledge in security protocolsDolev, D., Yao, A.C.-C.: On the security of public key protocols (extended abstract). In: FOCS, pp. 350–357 (1981)Escobar, S., Meadows, C., Meseguer, J.: A rewriting-based inference system for the NRL protocol analyzer and its meta-logical properties. Theoretical Computer Science 367(1-2), 162–202 (2006)Escobar, S., Meadows, C., Meseguer, J.: State Space Reduction in the Maude-NRL Protocol Analyzer. In: Jajodia, S., Lopez, J. (eds.) ESORICS 2008. LNCS, vol. 5283, pp. 548–562. Springer, Heidelberg (2008)Escobar, S., Meadows, C., Meseguer, J.: Maude-NPA: Cryptographic Protocol Analysis Modulo Equational Properties. In: Aldini, A., Barthe, G., Gorrieri, R. (eds.) FOSAD 2007. LNCS, vol. 5705, pp. 1–50. Springer, Heidelberg (2009)Escobar, S., Meadows, C., Meseguer, J., Santiago, S.: State space reduction in the maude-nrl protocol analyzer. Information and Computation (in press, 2012)Escobar, S., Sasse, R., Meseguer, J.: Folding variant narrowing and optimal variant termination. J. Log. Algebr. Program (in press, 2012)Thayer Fabrega, F.J., Herzog, J., Guttman, J.: Strand Spaces: What Makes a Security Protocol Correct? Journal of Computer Security 7, 191–230 (1999)Jouannaud, J.-P., Kirchner, H.: Completion of a set of rules modulo a set of equations. SIAM J. Comput. 15(4), 1155–1194 (1986)Küsters, R., Truderung, T.: Using ProVerif to analyze protocols with Diffie-Hellman exponentiation. In: CSF, pp. 157–171. IEEE Computer Society (2009)Küsters, R., Truderung, T.: Reducing protocol analysis with xor to the xor-free case in the horn theory based approach. Journal of Automated Reasoning 46(3-4), 325–352 (2011)Liu, Z., Lynch, C.: Efficient General Unification for XOR with Homomorphism. In: Bjørner, N., Sofronie-Stokkermans, V. (eds.) CADE 2011. LNCS, vol. 6803, pp. 407–421. Springer, Heidelberg (2011)Lowe, G., Roscoe, B.: Using csp to detect errors in the tmn protocol. IEEE Transactions on Software Engineering 23, 659–669 (1997)Lucas, S.: Context-sensitive computations in functional and functional logic programs. J. Functl. and Log. Progr. 1(4), 446–453 (1998)Meseguer, J.: Conditional rewriting logic as a united model of concurrency. Theor. Comput. Sci. 96(1), 73–155 (1992)Meseguer, J., Thati, P.: Symbolic reachability analysis using narrowing and its application to verification of cryptographic protocols. Higher-Order and Symbolic Computation 20(1-2), 123–160 (2007)Mödersheim, S.: Models and methods for the automated analysis of security protocols. PhD thesis, ETH Zurich (2007)Mödersheim, S., Viganò, L., Basin, D.A.: Constraint differentiation: Search-space reduction for the constraint-based analysis of security protocols. 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Tools and Algorithms for the Construction and Analysis of Systems

This open access two-volume set constitutes the proceedings of the 27th International Conference on Tools and Algorithms for the Construction and Analysis of Systems, TACAS 2021, which was held during March 27 – April 1, 2021, as part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2021. The conference was planned to take place in Luxembourg and changed to an online format due to the COVID-19 pandemic. The total of 41 full papers presented in the proceedings was carefully reviewed and selected from 141 submissions. The volume also contains 7 tool papers; 6 Tool Demo papers, 9 SV-Comp Competition Papers. The papers are organized in topical sections as follows: Part I: Game Theory; SMT Verification; Probabilities; Timed Systems; Neural Networks; Analysis of Network Communication. Part II: Verification Techniques (not SMT); Case Studies; Proof Generation/Validation; Tool Papers; Tool Demo Papers; SV-Comp Tool Competition Papers

Fundamental Approaches to Software Engineering

This open access book constitutes the proceedings of the 24th International Conference on Fundamental Approaches to Software Engineering, FASE 2021, which took place during March 27–April 1, 2021, and was held as part of the Joint Conferences on Theory and Practice of Software, ETAPS 2021. The conference was planned to take place in Luxembourg but changed to an online format due to the COVID-19 pandemic. The 16 full papers presented in this volume were carefully reviewed and selected from 52 submissions. The book also contains 4 Test-Comp contributions

A Reduced Semantics for Deciding Trace Equivalence

Many privacy-type properties of security protocols can be modelled using trace equivalence properties in suitable process algebras. It has been shown that such properties can be decided for interesting classes of finite processes (i.e., without replication) by means of symbolic execution and constraint solving. However, this does not suffice to obtain practical tools. Current prototypes suffer from a classical combinatorial explosion problem caused by the exploration of many interleavings in the behaviour of processes. M\"odersheim et al. have tackled this problem for reachability properties using partial order reduction techniques. We revisit their work, generalize it and adapt it for equivalence checking. We obtain an optimisation in the form of a reduced symbolic semantics that eliminates redundant interleavings on the fly. The obtained partial order reduction technique has been integrated in a tool called APTE. We conducted complete benchmarks showing dramatic improvements.Comment: Accepted for publication in LMC

Theory and Implementation of Software Bounded Model Checking

This thesis provides a detailed overview of the theory of software bounded model checking (SBMC) and its implementation in LLBMC, which is based on the LLVM compiler framework. The whole process from a C program to an SMT formula is described in detail. Furthermore, a theory of dynamic memory allocation is introduced which allows modelling C\u27s memory model with high precision. Finally, it is shown that LLBMC\u27s approach to software bounded model checking performs well compared to competing tools

On Equivalences, Metrics, and Computational Indistinguishability

The continuous technological progress and the constant growing of information flow we observe every day, brought us an urgent need to find a way to defend our data from malicious intruders; cryptography is the field of computer science that deals with security and studies techniques to protect communications from third parties, but in the recent years there has been a crisis in proving the security of cryptographic protocols, due to the exponential increase in the complexity of modeling proofs. In this scenario we study interactions in a typed lambda-calculus properly defined to fit well into the key aspects of a cryptographic proof: interaction, complexity and probability. This calculus, RSLR, is an extension of Hofmann's SLR for probabilistic polynomial time computations and it is perfect to model cryptographic primitives and adversaries. In particular, we characterize notions of context equivalence and context metrics, when defined on linear contexts, by way of traces, making proofs easier. Furthermore we show how to use this techniqe to obtain a proof methodology for computational indistinguishability, a key notion in modern cryptography; finally we give some motivating examples of concrete cryptographic schemes

Programming Languages and Systems

This open access book constitutes the proceedings of the 31st European Symposium on Programming, ESOP 2022, which was held during April 5-7, 2022, in Munich, Germany, as part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2022. The 21 regular papers presented in this volume were carefully reviewed and selected from 64 submissions. They deal with fundamental issues in the specification, design, analysis, and implementation of programming languages and systems