In this self-contained textbook the authors introduce the theoretical foundations of the Random Oracle methodology. They describe both recent achievements in the study of Random Oracle instantiations as well as various classical results. 

After motivating the authors' unique approach, Chap. 2 introduces the concepts from computability theory, probability theory, information theory, complexity theory, and  information-theoretic security that are required to understand the book content. The chapters in Part I, Foundations, introduce hash functions and their basic properties. The authors explain the foundations of modern cryptography, introduce various cryptographic concepts and primitives, and relevant proof techniques. The specific topics covered are computational security, pseudorandomness and computational indistinguishability, collision resistance, encryption schemes, signature schemes, and non-cryptographic hashing. Part II, The Random Oracle Methodology, introduces random oracles and discusses the random oracle methodology. In Part III, Hash Function Constructions, the authors explain how to construct cryptographic hash functions in practice. 

The text is supported with exercises, notes, references, and pointers to further reading, and it is a suitable textbook for advanced undergraduate students, graduate students, and researchers of cryptology and information security.