applied cryptography

Ensuring functional correctness and performance resilience of network protocols under component failures and adversarial attacks remains a significant challenge. Method: This paper proposes a synergistic analysis framework integrating formal verification with attack synthesis. It models protocol behavior using a formal specification language and employs logical predicates, trace analysis, and model checking to achieve closed-loop verification—simultaneously establishing correctness guarantees and automatically generating realistic attack scenarios. Contribution/Results: Diverging from conventional unidirectional verification, our approach innovatively embeds attack-path generation directly into the verification workflow, enabling reproducible and interpretable failure attribution. Experimental evaluation across multiple mainstream network protocols demonstrates substantial improvements in vulnerability detection rates and attack-surface characterization accuracy. The results validate the feasibility and practicality of formal methods for deep, security-critical analysis of complex network protocols.

This work addresses the limitations of current cryptographic APIs, which are tightly coupled to specific algorithms and lack policy-driven control and key migration capabilities, thereby hindering smooth transitions to post-quantum cryptography. To overcome these challenges, the paper proposes a novel API architecture designed for cryptographic agility, grounded in five core principles: abstraction, stability, temporal flexibility, separation of concerns, and extensibility. By introducing scoped intent vocabularies and abstract policy interfaces, the design decouples algorithm selection from key management. Leveraging Protocol Buffers schemas alongside stable key identifiers and evolvable operations—such as rotation, transformation, and migration—the approach transforms algorithm updates into operational procedures that require no application code changes, significantly enhancing the feasibility and efficiency of migrating systems to post-quantum cryptographic standards.

Protocol designers often face a high barrier to entry in using formal verification tools such as ProVerif and Tamarin due to the lack of systematic guidance on translating security properties into executable models. This work addresses this gap by conducting a systematic review of 53 studies published between 2022 and 2025, resulting in the first comprehensive taxonomy of security properties tailored to mainstream verification tools. The taxonomy integrates informal explanations, first-order logic definitions, and tool-specific modeling exemplars. By bridging the gap between theoretical formulations and practical modeling, this study significantly enhances the accuracy and efficiency of protocol modeling. An accompanying open-source repository of illustrative examples further lowers the practical barrier to adopting formal verification in real-world protocol design.

Formal security analysis of closed-source encrypted applications (e.g., WhatsApp) remains intractable due to the absence of source code and cryptographic specifications. Method: We propose the first automated framework unifying functional correctness verification with microarchitectural side-channel resilience analysis. Leveraging Ghidra and an extended CryptoBAP, we perform binary-level reverse engineering to extract a formal model of WhatsApp’s encryption protocol—its first such model. We introduce hardware leakage contracts and integrate them with the DeepSec prover to jointly verify functional flaws and side-channel vulnerabilities. Contribution/Results: Our analysis uncovers previously unknown privacy violations invisible at the specification level—including contact leakage—and identifies a unlinkability attack against the BAC protocol. We formally verify forward secrecy, confirm susceptibility to cloning attacks, and expose deviations from the protocol specification. Crucially, we establish a reproducible, scalable, side-channel-aware formal analysis methodology for closed-source cryptographic software.

High-level security properties (e.g., confidentiality, integrity) in the Software Development Life Cycle (SDLC) lack systematic refinement mechanisms, leading to semantic disconnects between these properties and concrete artifacts such as threats, defenses, and assets. Method: We propose the first SDLC-wide security property refinement taxonomy, implemented as a formal, refinable, verifiable, and traceable classification framework in Event-B. The framework integrates principles from security engineering and adaptive systems theory. Contribution: It bridges the semantic gap between high-level security objectives and mid-to-low-level security models, enabling co-evolution of security properties with threat and defense models. Rigorously verified in Event-B, the framework ensures logical consistency and correctness. It provides both theoretically sound foundations and practically actionable guidance for security requirements–driven system development.

This work addresses the high barrier to entry in formal verification of cryptographic protocols and the difficulty of tracing verification results back to concrete implementations. The authors propose a domain-specific language (DSL)-centric development methodology that pioneers a “language-first” modeling paradigm. Their approach automatically translates protocol implementations into Tamarin-verifiable models and integrates symbolic execution to ensure memory safety. This framework guarantees that general trace properties established through formal verification are correctly mapped back to the original source code. Empirical evaluation demonstrates the successful generation of precise models for Signed Diffie-Hellman and WireGuard protocols; notably, the resulting WireGuard implementation achieves interoperability, practical usability, and compositional security guarantees.

This study addresses the challenge that organizations lack structured awareness of cryptographic assets in software, which impedes effective security governance and post-quantum migration. To bridge this gap, the authors propose a static analysis approach that introduces the first taxonomy tailored for Cryptographic Bill of Materials (CBOM) and designs an extensible, scanner-agnostic rule library to enable efficient discovery and risk assessment of cryptographic assets. Empirical evaluation demonstrates that the method processes 57,610 files within six minutes, accurately identifying 370 cryptographic assets with an F1 score of 0.75. It further uncovers six CVE-listed vulnerabilities and 52 candidates requiring post-quantum migration, achieving a vulnerability labeling accuracy of 91%.

This study addresses the prevailing overemphasis on technical aspects in current research on integrating post-quantum cryptography (PQC) into software systems, which largely overlooks the critical interplay of human and organizational factors. Drawing upon a Human–Organization–Technology (HOT) triadic framework, the work employs a Systematization of Knowledge (SoK) methodology to conduct a cross-dimensional, structured analysis of existing PQC implementation literature. It introduces the first PQC-HOT integration model, elucidating the interdependencies and mutual constraints among the three dimensions and thereby transcending conventional paradigms focused solely on algorithmic performance. The proposed model not only conceptualizes PQC deployment as a socio-technical systemic transformation but also offers practitioners a systematic decision-support framework while outlining future research directions and design implications for sustainable and scalable PQC transitions.

This work addresses a central challenge in system security: formally verifying that system designs and implementations satisfy intended safety properties and support security certification. The authors propose a systematic approach grounded in proof assistants, integrating interactive theorem proving and formal methods to precisely model and machine-check critical security properties across diverse domains—including system security, language-level security, secure compilation, and cryptography. By enabling rigorous, machine-verifiable proofs of correctness, this methodology significantly strengthens the formal assurance of security properties and provides a unified theoretical framework and toolchain for constructing verifiable and certifiable secure systems.