arXiv subjects

Amir M. Ahmadian

Publications and source records attributed to Amir M. Ahmadian.

3 recordsLinked to original sources

arXiv2026

Statistical Verification of Quantitative Hyperproperties: Beyond Boolean Quantification

Formalisms for hyperproperties provide a solid foundation for studying the verification problem across classes of relational properties, such as those in information flow control (IFC). However, existing formalisms remain limited in expressiveness when it comes to capturing practical aspects of real-world systems. In particular, they do not adequately account for the quantitative nature of such systems. In this paper, we address this gap by revisiting the specification and verification of hyperproperties from a quantitative, measure-based, perspective. We introduce Quantitative Hyper-Logic (QHL), which replaces qualitative trace quantifiers with measure-based ones and extends temporal predicates with richer quantitative expressions. We further study the verification problem from a statistical verification point of view, and develop algorithms for the statistical verification of QHL specifications. For the introduced measure-based quantifiers, we particularly provide an analysis in terms of sample complexity and achievable statistical guarantees. In particular, we show how statistical methods such as Hoeffding's inequality and extreme value theory can be combined to develop statistical verification algorithms for nested measure-based quantifiers. Our approach provides quantitative alternatives for where traditional verification methods become infeasible. We demonstrate both expressiveness and efficacy on benchmarks from quantitative IFC, comparing against qualitative methods.

cs.LO↗

arXiv2025

Securing P4 Programs by Information Flow Control

Software-Defined Networking (SDN) has transformed network architectures by decoupling the control and data-planes, enabling fine-grained control over packet processing and forwarding. P4, a language designed for programming data-plane devices, allows developers to define custom packet processing behaviors directly on programmable network devices. This provides greater control over packet forwarding, inspection, and modification. However, the increased flexibility provided by P4 also brings significant security challenges, particularly in managing sensitive data and preventing information leakage within the data-plane. This paper presents a novel security type system for analyzing information flow in P4 programs that combines security types with interval analysis. The proposed type system allows the specification of security policies in terms of input and output packet bit fields rather than program variables. We formalize this type system and prove it sound, guaranteeing that well-typed programs satisfy noninterference. Our prototype implementation, Tap4s, is evaluated on several use cases, demonstrating its effectiveness in detecting security violations and information leakages.

cs.CR↗

arXiv2024

Disjunctive Policies for Database-Backed Programs

When specifying security policies for databases, it is often natural to formulate disjunctive dependencies, where a piece of information may depend on at most one of two dependencies P1 or P2, but not both. A formal semantic model of such disjunctive dependencies, the Quantale of Information, was recently introduced by Hunt and Sands as a generalization of the Lattice of Information. In this paper, we seek to contribute to the understanding of disjunctive dependencies in database-backed programs and introduce a practical framework to statically enforce disjunctive security policies. To that end, we introduce the Determinacy Quantale, a new query-based structure which captures the ordering of disjunctive information in databases. This structure can be understood as a query-based counterpart to the Quantale of Information. Based on this structure, we design a sound enforcement mechanism to check disjunctive policies for database-backed programs. This mechanism is based on a type-based analysis for a simple imperative language with database queries, which is precise enough to accommodate a variety of row- and column-level database policies flexibly while keeping track of disjunctions due to control flow. We validate our mechanism by implementing it in a tool, DiVerT, and demonstrate its feasibility on a number of use cases.

cs.CR↗