14,754 research outputs found
Qafny: Quantum Program Verification Through Type-guided Classical Separation Logic
Formal verification has been proven instrumental to ensure that quantum
programs implement their specifications but often requires a significant
investment of time and labor. To address this challenge, we present Qafny, an
automated proof system designed for verifying quantum programs. At its core,
Qafny uses a type-guided quantum proof system that translates quantum
operations to classical array operations. By modeling these operations as proof
rules within a classical separation logic framework, Qafny automates much of
the traditionally tedious and time-consuming reasoning process. We prove the
soundness and completeness of our proof system and implement a prototype
compiler that transforms Qafny programs both into the Dafny programming
language and into executable quantum circuits. Using Qafny, we demonstrate how
to efficiently verify important quantum algorithms, including quantum-walk
algorithms, Grover's search algorithm, and Shor's factoring algorithm, with
significantly reduced human effort.Comment: Version
Reachability and Termination Analysis of Concurrent Quantum Programs
We introduce a Markov chain model of concurrent quantum programs. This model
is a quantum generalization of Hart, Sharir and Pnueli's probabilistic
concurrent programs. Some characterizations of the reachable space, uniformly
repeatedly reachable space and termination of a concurrent quantum program are
derived by the analysis of their mathematical structures. Based on these
characterizations, algorithms for computing the reachable space and uniformly
repeatedly reachable space and for deciding the termination are given.Comment: Accepted by Concur'12. Comments are welcom
Symbolic Abstractions for Quantum Protocol Verification
Quantum protocols such as the BB84 Quantum Key Distribution protocol exchange
qubits to achieve information-theoretic security guarantees. Many variants
thereof were proposed, some of them being already deployed. Existing security
proofs in that field are mostly tedious, error-prone pen-and-paper proofs of
the core protocol only that rarely account for other crucial components such as
authentication. This calls for formal and automated verification techniques
that exhaustively explore all possible intruder behaviors and that scale well.
The symbolic approach offers rigorous, mathematical frameworks and automated
tools to analyze security protocols. Based on well-designed abstractions, it
has allowed for large-scale formal analyses of real-life protocols such as TLS
1.3 and mobile telephony protocols. Hence a natural question is: Can we use
this successful line of work to analyze quantum protocols? This paper proposes
a first positive answer and motivates further research on this unexplored path
Fifty years of Hoare's Logic
We present a history of Hoare's logic.Comment: 79 pages. To appear in Formal Aspects of Computin
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