Quantifying Dynamic Leakage: Complexity Analysis and Model Counting-based Calculation

by   Bao Trung Chu, et al.

A program is non-interferent if it leaks no secret information to an observable output. However, non-interference is too strict in many practical cases and quantitative information flow (QIF) has been proposed and studied in depth. Originally, QIF is defined as the average of leakage amount of secret information over all executions of a program. However, a vulnerable program that has executions leaking the whole secret but has the small average leakage could be considered as secure. This counter-intuition raises a need for a new definition of information leakage of a particular run, i.e., dynamic leakage. As discussed in [5], entropy-based definitions do not work well for quantifying information leakage dynamically; Belief-based definition on the other hand is appropriate for deterministic programs, however, it is not appropriate for probabilistic ones. In this paper, we propose new simple notions of dynamic leakage based on entropy which are compatible with existing QIF definitions for deterministic programs, and yet reasonable for probabilistic programs in the sense of [5]. We also investigated the complexity of computing the proposed dynamic leakage for three classes of Boolean programs. We also implemented a tool for QIF calculation using model counting tools for Boolean formulae. Experimental results on popular benchmarks of QIF research show the flexibility of our framework. Finally, we discuss the improvement of performance and scalability of the proposed method as well as an extension to more general cases.


page 1

page 2

page 3

page 4


On the Compositionality of Dynamic Leakage and Its Application to the Quantification Problem

Quantitative information flow (QIF) is traditionally defined as the expe...

Generalised Entropies and Metric-Invariant Optimal Countermeasures for Information Leakage under Symmetric Constraints

We introduce a novel generalization of entropy and conditional entropy f...

Quantitative Verification of Masked Arithmetic Programs against Side-Channel Attacks

Power side-channel attacks, which can deduce secret data via statistical...

What's the Over/Under? Probabilistic Bounds on Information Leakage

Quantitative information flow (QIF) is concerned with measuring how much...

Cumulant Expansion of Mutual Information for Quantifying Leakage of a Protected Secret

The information leakage of a cryptographic implementation with a given d...

Output-sensitive Information flow analysis

Constant-time programming is a countermeasure to prevent cache based att...

Parametric Timed Model Checking for Guaranteeing Timed Opacity

Information leakage can have dramatic consequences on systems security. ...

Please sign up or login with your details

Forgot password? Click here to reset