Hash functions are the cryptographer's Swiss Army knife. Even though they play an integral part in today's cryptography, existing textbooks discuss hash functions only in passing and instead often put an emphasis on other primitives like encryption schemes. In this book the authors take a different approach and place hash functions at the center. The result is not only an introduction to the theory of hash functions and the random oracle model but a comprehensive introduction to modern cryptography. After motivating their unique approach, in the first chapter the authors introduce the concepts from computability theory, probability theory, information theory, complexity theory, and information-theoretic security that are required to understand the book content. In Part I they introduce the foundations of hash functions and modern cryptography. They cover a number of schemes, concepts, and proof techniques, including computational security, one-way functions, pseudorandomness and pseudorandom functions, game-based proofs, message authentication codes, encryption schemes, signature schemes, and collision-resistant (hash) functions. In Part II the authors explain the random oracle model, proof techniques used with random oracles, random oracle constructions, and examples of real-world random oracle schemes. They also address the limitations of random oracles and the random oracle controversy, the fact that uninstantiable schemes exist which are provably secure in the random oracle model but which become insecure with any real-world hash function. Finally in Part III the authors focus on constructions of hash functions. This includes a treatment of iterative hash functions and generic attacks against hash functions, constructions of hash functions based on block ciphers and number-theoretic assumptions, a discussion of privately keyed hash functions including a full security proof for HMAC, and a presentation of real-world hash functions. The text is supported with exercises, notes, references, and pointers to further reading, and it is a suitable textbook for undergraduate and graduate students, and researchers of cryptology and information security.

The two-volume proceedings LNCS 9056 + 9057 constitutes the proceedings of the 34th Annual International Conference on the Theory and Applications of Cryptographic Techniques, EUROCRYPT 2015, held in Sofia, Bulgaria, in April 2015. The 57 full papers included in these volumes were carefully reviewed and selected from 194 submissions. The papers are organized in topical sections named: honorable mentions, random number generators, number field sieve, algorithmic cryptanalysis, symmetric cryptanalysis, hash functions, evaluation implementation, masking, fully homomorphic encryption, related-key attacks, fully monomorphic encryption, efficient two-party protocols, symmetric cryptanalysis, lattices, signatures, zero-knowledge proofs, leakage-resilient cryptography, garbled circuits, crypto currencies, secret sharing, outsourcing computations, obfuscation and e-voting, multi-party computations, encryption, resistant protocols, key exchange, quantum cryptography, and discrete logarithms.

The two-volume proceedings LNCS 9056 + 9057 constitutes the proceedings of the 34th Annual International Conference on the Theory and Applications of Cryptographic Techniques, EUROCRYPT 2015, held in Sofia, Bulgaria, in April 2015. The 57 full papers included in these volumes were carefully reviewed and selected from 194 submissions. The papers are organized in topical sections named: honorable mentions, random number generators, number field sieve, algorithmic cryptanalysis, symmetric cryptanalysis, hash functions, evaluation implementation, masking, fully homomorphic encryption, related-key attacks, fully monomorphic encryption, efficient two-party protocols, symmetric cryptanalysis, lattices, signatures, zero-knowledge proofs, leakage-resilient cryptography, garbled circuits, crypto currencies, secret sharing, outsourcing computations, obfuscation and e-voting, multi-party computations, encryption, resistant protocols, key exchange, quantum cryptography, and discrete logarithms.

Johannes Buchmann is internationally recognized as one of the leading figures in areas of computational number theory, cryptography and information security. He has published numerous scientific papers and books spanning a very wide spectrum of interests; besides R&D he also fulfilled lots of administrative tasks for instance building up and directing his research group CDC at Darmstadt, but he also served as the Dean of the Department of Computer Science at TU Darmstadt and then went on to become Vice President of the university for six years (2001-2007). This festschrift, published in honor of Johannes Buchmann on the occasion of his 60th birthday, contains contributions by some of his colleagues, former students and friends. The papers give an overview of Johannes Buchmann's research interests, ranging from computational number theory and the hardness of cryptographic assumptions to more application-oriented topics such as privacy and hardware security. With this book we celebrate Johannes Buchmann's vision and achievements.

This book constitutes the refereed proceedings of the 15th International Conference on Practice and Theory in Public Key Cryptography, PKC 2012, held in Darmstadt, Germany, in May 2012. The 41 papers presented were carefully reviewed and selected from 188 submissions. The book also contains one invited talk. The papers are organized in the following topical sections: homomorphic encryption and LWE, signature schemes, code-based and multivariate crypto, public key encryption: special properties, identity-based encryption, public-key encryption: constructions, secure two-party and multi-party computations, key exchange and secure sessions, public-key encryption: relationships, DL, DDH, and more number theory, and beyond ordinary signature schemes.

This book constitutes the refereed proceedings of the Cryptographers' Track at the RSA Conference 2009, CT-RSA 2009, held in San Francisco, CA, USA in April 2009.

The 31 revised full papers presented were carefully reviewed and selected from 93 submissions. The papers are organized in topical sections on identity-based encryption, protocol analysis, two-party protocols, more than signatures, collisions for hash functions, cryptanalysis, alternative encryption, privacy and anonymity, efficiency improvements, multi-party protocols, security of encryption schemes as well as countermeasures and faults.

The two-volume proceedings LNCS 9665 + LNCS 9666 constitutes the thoroughly refereed proceedings of the 35th Annual International Conference on the Theory and Applications of Cryptographic Techniques, EUROCRYPT 2016, held in Vienna, Austria, in May 2016. The 62 full papers included in these volumes were carefully reviewed and selected from 274 submissions. The papers are organized in topical sections named: (pseudo)randomness; LPN/LWE; cryptanalysis; masking; fully homomorphic encryption; number theory; hash functions; multilinear maps; message authentification codes; attacks on SSL/TLS; real-world protocols; robust designs; lattice reduction; latticed-based schemes; zero-knowledge; pseudorandom functions; multi-party computation; separations; protocols; round complexity; commitments; lattices; leakage; in differentiability; obfuscation; and automated analysis, functional encryption, and non-malleable codes.

The two-volume proceedings LNCS 9665 + 9666 constitutes the thoroughly refereed proceedings of the 35th Annual International Conference on the Theory and Applications of Cryptographic Techniques, EUROCRYPT 2016, held in Vienna, Austria, in May 2016. The 62 full papers included in these volumes were carefully reviewed and selected from 274 submissions. The papers are organized in topical sections named: (pseudo)randomness; LPN/LWE; cryptanalysis; masking; fully homomorphic encryption; number theory; hash functions; multilinear maps; message authentification codes; attacks on SSL/TLS; real-world protocols; robust designs; lattice reduction; latticed-based schemes; zero-knowledge; pseudorandom functions; multi-party computation; separations; protocols; round complexity; commitments; lattices; leakage; in differentiability; obfuscation; and automated analysis, functional encryption, and non-malleable codes.

Hash functions are the cryptographer's Swiss Army knife. Even though they play an integral part in today's cryptography, existing textbooks discuss hash functions only in passing and instead often put an emphasis on other primitives like encryption schemes. In this book the authors take a different approach and place hash functions at the center. The result is not only an introduction to the theory of hash functions and the random oracle model but a comprehensive introduction to modern cryptography. After motivating their unique approach, in the first chapter the authors introduce the concepts from computability theory, probability theory, information theory, complexity theory, and information-theoretic security that are required to understand the book content. In Part I they introduce the foundations of hash functions and modern cryptography. They cover a number of schemes, concepts, and proof techniques, including computational security, one-way functions, pseudorandomness and pseudorandom functions, game-based proofs, message authentication codes, encryption schemes, signature schemes, and collision-resistant (hash) functions. In Part II the authors explain the random oracle model, proof techniques used with random oracles, random oracle constructions, and examples of real-world random oracle schemes. They also address the limitations of random oracles and the random oracle controversy, the fact that uninstantiable schemes exist which are provably secure in the random oracle model but which become insecure with any real-world hash function. Finally in Part III the authors focus on constructions of hash functions. This includes a treatment of iterative hash functions and generic attacks against hash functions, constructions of hash functions based on block ciphers and number-theoretic assumptions, a discussion of privately keyed hash functions including a full security proof for HMAC, and a presentation of real-world hash functions. The text is supported with exercises, notes, references, and pointers to further reading, and it is a suitable textbook for undergraduate and graduate students, and researchers of cryptology and information security.