2,069 papers · page 27 of 104
High-performance multithreaded software often relies on optimized implementations of common abstract data types (ADTs) like counters, key-value stores, and queues, i.e., concurrent objects . By using fine-grained and non-blocking mechanisms for efficient inter-thread synchronizat…
We present SecCSL , a concurrent separation logic for proving expressive, data-dependent information flow security properties of low-level programs. SecCSL is considerably more expressive, while being simpler, than recent compositional information flow logics that cannot reason a…
We propose an automated verification technique for hypersafety properties, which express sets of valid interrelations between multiple finite runs of a program. The key observation is that constructing a proof for a small representative set of the runs of the product program (i.e…
With ever increasing autonomy of cyber-physical systems, monitoring becomes an integral part for ensuring the safety of the system at runtime. $$\text {StreamLAB} $$ is a monitoring framework with high degree of expressibility and strong correctness guarantees. Specifications are…
Programs with arrays are ubiquitous. Automated reasoning about arrays necessitates discovering properties about ranges of elements at certain program points. Such properties are formally specified by universally quantified formulas, which are difficult to find, and difficult to p…
Infinite-state systems such as distributed protocols are challenging to verify using interactive theorem provers or automatic verification tools. Of these techniques, deductive verification is highly expressive but requires the user to annotate the system with inductive invariant…
Delayed coupling between state variables occurs regularly in technical dynamical systems, especially embedded control. As it consequently is omnipresent in safety-critical domains, there is an increasing interest in the safety verification of systems modelled by Delay Differentia…
Reactive systems that operate in environments with complex data, such as mobile apps or embedded controllers with many sensors, are difficult to synthesize. Synthesis tools usually fail for such systems because the state space resulting from the discretization of the data is too …
We consider the problem whether termination of affine integer loops is decidable. Since Tiwari conjectured decidability in 2004 [ 15 ], only special cases have been solved [ 3 , 4 , 14 ]. We complement this work by proving decidability for the case that the update matrix is trian…
We formulate numerically-robust inductive proof rules for unbounded stability and safety properties of continuous dynamical systems. These induction rules robustify standard notions of Lyapunov functions and barrier certificates so that they can tolerate small numerical errors. I…
A popular method for solving reachability in timed automata proceeds by enumerating reachable sets of valuations represented as zones. A naïve enumeration of zones does not terminate. Various termination mechanisms have been studied over the years. Coming up with efficient termin…
We present Dartagnan , a bounded model checker (BMC) for concurrent programs under weak memory models. Its distinguishing feature is that the memory model is not implemented inside the tool but taken as part of the input. Dartagnan reads CAT , the standard language for memory mod…
We show how to verify that large data center networks satisfy key properties such as all-pairs reachability under a bounded number of faults. To scale the analysis, we develop algorithms that identify network symmetries and compute small abstract networks from large concrete ones…
Formal verification of real-time systems is attractive because these systems often perform critical operations. Unlike non real-time systems, latency and response time guarantees are of critical importance in this setting, as much as functional correctness. Nevertheless, formal v…
Probabilistic bisimulation is a fundamental notion of process equivalence for probabilistic systems. It has important applications, including the formalisation of the anonymity property of several communication protocols. While there is a large body of work on verifying probabili…
We consider the problem of automatically establishing that a given syntax-guided-synthesis (SyGuS) problem is unrealizable (i.e., has no solution). Existing techniques have quite limited ability to establish unrealizability for general SyGuS instances in which the grammar describ…
We introduce first-order alternating automata, a generalization of boolean alternating automata, in which transition rules are described by multisorted first-order formulae, with states and internal variables given by uninterpreted predicate terms. The model is closed under union…
We develop a compositional, algebraic theory of skipping refinement, as well as local proof methods to effectively analyze the correctness of optimized reactive systems. A verification methodology based on refinement involves showing that any infinite behavior of an optimized low…
We present the first stable release of our tool Q3B for deciding satisfiability of quantified bit-vector formulas. Unlike other state-of-the-art solvers for this problem, Q3B is based on translation of a formula to a bdd that represents models of the formula. The tool also employ…
System development often involves decisions about how a high-level design is to be implemented using primitives from a low-level platform. Certain decisions, however, may introduce undesirable behavior into the resulting implementation, possibly leading to a violation of a desire…