This book presents a comprehensive mathematical theory that explains precisely what information flow is, how it can be assessed quantitatively - so bringing precise meaning to the intuition that certain information leaks are small enough to be tolerated - and how systems can be constructed that achieve rigorous, quantitative information-flow guarantees in those terms. It addresses the fundamental challenge that functional and practical requirements frequently conflict with the goal of preserving confidentiality, making perfect security unattainable. Topics include: a systematic presentation of how unwanted information flow, i.e., "leaks", can be quantified in operationally significant ways and then bounded, both with respect to estimated benefit for an attacking adversary and by comparisons between alternative implementations; a detailed study of capacity, refinement, and Dalenius leakage, supporting robust leakage assessments; a unification of information-theoretic channels and information-leaking sequential programs within the same framework; and a collection of case studies, showing how the theory can be applied to interesting realistic scenarios. The text is unified, self-contained and comprehensive, accessible to students and researchers with some knowledge of discrete probability and undergraduate mathematics, and contains exercises to facilitate its use as a course textbook.

This Festschrift was published in honor of Catuscia Palamidessi on the occasion of her 60th birthday. It features 6 laudations, which are available in the front matter of the volume, and 25 papers by close collaborators and friends. The papers are organized in topical sections named: concurrency; logic and constraint programming; security and privacy; and models and puzzles. These contributions are a tribute to Catuscia Palamidessi's intellectual depth, vision, passion for science, and tenacity in solving technical problems. They also reflect the breadth and impact of her work. Her scientific interests include, in chronological order, principles of programming languages, concurrency theory, security, and privacy.