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76
Random Oracles are Practical: A Paradigm for Designing Efficient Protocols
, 1995
"... We argue that the random oracle model  where all parties have access to a public random oracle  provides a bridge between cryptographic theory and cryptographic practice. In the paradigm we suggest, a practical protocol P is produced by first devising and proving correct a protocol P R for the ..."
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Cited by 1425 (67 self)
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We argue that the random oracle model  where all parties have access to a public random oracle  provides a bridge between cryptographic theory and cryptographic practice. In the paradigm we suggest, a practical protocol P is produced by first devising and proving correct a protocol P R for the random oracle model, and then replacing oracle accesses by the computation of an "appropriately chosen" function h. This paradigm yields protocols much more efficient than standard ones while retaining many of the advantages of provable security. We illustrate these gains for problems including encryption, signatures, and zeroknowledge proofs.
Entity Authentication and Key Distribution
, 1993
"... Entity authentication and key distribution are central cryptographic problems in distributed computing  but up until now, they have lacked even a meaningful definition. One consequence is that incorrect and inefficient protocols have proliferated. This paper provides the first treatment of these p ..."
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Cited by 496 (12 self)
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Entity authentication and key distribution are central cryptographic problems in distributed computing  but up until now, they have lacked even a meaningful definition. One consequence is that incorrect and inefficient protocols have proliferated. This paper provides the first treatment of these problems in the complexitytheoretic framework of modern cryptography. Addressed in detail are two problems of the symmetric, twoparty setting: mutual authentication and authenticated key exchange. For each we present a definition, protocol, and proof that the protocol meets its goal, assuming the (minimal) assumption of pseudorandom function. When this assumption is appropriately instantiated, the protocols given are practical and efficient.
Relations among notions of security for publickey encryption schemes
, 1998
"... Abstract. We compare the relative strengths of popular notions of security for public key encryption schemes. We consider the goals of privacy and nonmalleability, each under chosen plaintext attack and two kinds of chosen ciphertext attack. For each of the resulting pairs of definitions we prove e ..."
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Cited by 472 (66 self)
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Abstract. We compare the relative strengths of popular notions of security for public key encryption schemes. We consider the goals of privacy and nonmalleability, each under chosen plaintext attack and two kinds of chosen ciphertext attack. For each of the resulting pairs of definitions we prove either an implication (every scheme meeting one notion must meet the other) or a separation (there is a scheme meeting one notion but not the other, assuming the first notion can be met at all). We similarly treat plaintext awareness, a notion of security in the random oracle model. An additional contribution of this paper is a new definition of nonmalleability which we believe is simpler than the previous one.
Security and Composition of Multiparty Cryptographic Protocols
 JOURNAL OF CRYPTOLOGY
, 1998
"... We present general definitions of security for multiparty cryptographic protocols, with focus on the task of evaluating a probabilistic function of the parties' inputs. We show that, with respect to these definitions, security is preserved under a natural composition operation. The definiti ..."
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Cited by 415 (19 self)
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We present general definitions of security for multiparty cryptographic protocols, with focus on the task of evaluating a probabilistic function of the parties' inputs. We show that, with respect to these definitions, security is preserved under a natural composition operation. The definitions follow the general paradigm of known definitions; yet some substantial modifications and simplifications are introduced. The composition operation is the natural `subroutine substitution' operation, formalized by Micali and Rogaway. We consider several standard settings for multiparty protocols, including the cases of eavesdropping, Byzantine, nonadaptive and adaptive adversaries, as well as the informationtheoretic and the computational models. In particular, in the computational model we provide the first definition of security of protocols that is shown to be preserved under composition.
A Concrete Security Treatment of Symmetric Encryption
 Proceedings of the 38th Symposium on Foundations of Computer Science, IEEE
, 1997
"... We study notions and schemes for symmetric (ie. private key) encryption in a concrete security framework. We give four di erent notions of security against chosen plaintext attack and analyze the concrete complexity ofreductions among them, providing both upper and lower bounds, and obtaining tight ..."
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Cited by 375 (61 self)
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We study notions and schemes for symmetric (ie. private key) encryption in a concrete security framework. We give four di erent notions of security against chosen plaintext attack and analyze the concrete complexity ofreductions among them, providing both upper and lower bounds, and obtaining tight relations. In this way we classify notions (even though polynomially reducible to each other) as stronger or weaker in terms of concrete security. Next we provide concrete security analyses of methods to encrypt using a block cipher, including the most popular encryption method, CBC. We establish tight bounds (meaning
Reconciling Two Views of Cryptography (The Computational Soundness of Formal Encryption)
, 2000
"... Two distinct, rigorous views of cryptography have developed over the years, in two mostly separate communities. One of the views relies on a simple but effective formal approach; the other, on a detailed computational model that considers issues of complexity and probability. ..."
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Cited by 344 (18 self)
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Two distinct, rigorous views of cryptography have developed over the years, in two mostly separate communities. One of the views relies on a simple but effective formal approach; the other, on a detailed computational model that considers issues of complexity and probability.
Authenticated encryption: Relations among notions and analysis of the generic composition paradigm
, 2000
"... and analysis of the generic composition paradigm ..."
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Cited by 242 (25 self)
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and analysis of the generic composition paradigm
ChosenCiphertext Security from IdentityBased Encryption. Adv
 in Cryptology — Eurocrypt 2004, LNCS
, 2004
"... We propose simple and efficient CCAsecure publickey encryption schemes (i.e., schemes secure against adaptive chosenciphertext attacks) based on any identitybased encryption (IBE) scheme. Our constructions have ramifications of both theoretical and practical interest. First, our schemes give a n ..."
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Cited by 217 (12 self)
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We propose simple and efficient CCAsecure publickey encryption schemes (i.e., schemes secure against adaptive chosenciphertext attacks) based on any identitybased encryption (IBE) scheme. Our constructions have ramifications of both theoretical and practical interest. First, our schemes give a new paradigm for achieving CCAsecurity; this paradigm avoids “proofs of wellformedness ” that have been shown to underlie previous constructions. Second, instantiating our construction using known IBE constructions we obtain CCAsecure encryption schemes whose performance is competitive with the most efficient CCAsecure schemes to date. Our techniques extend naturally to give an efficient method for securing also IBE schemes (even hierarchical ones) against adaptive chosenciphertext attacks. Coupled with previous work, this gives the first efficient constructions of CCAsecure IBE schemes. 1