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Universally composable security: A new paradigm for cryptographic protocols
, 2013
"... We present a general framework for representing cryptographic protocols and analyzing their security. The framework allows specifying the security requirements of practically any cryptographic task in a unified and systematic way. Furthermore, in this framework the security of protocols is preserved ..."
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Cited by 831 (37 self)
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We present a general framework for representing cryptographic protocols and analyzing their security. The framework allows specifying the security requirements of practically any cryptographic task in a unified and systematic way. Furthermore, in this framework the security of protocols is preserved under a general protocol composition operation, called universal composition. The proposed framework with its securitypreserving composition operation allows for modular design and analysis of complex cryptographic protocols from relatively simple building blocks. Moreover, within this framework, protocols are guaranteed to maintain their security in any context, even in the presence of an unbounded number of arbitrary protocol instances that run concurrently in an adversarially controlled manner. This is a useful guarantee, that allows arguing about the security of cryptographic protocols in complex and unpredictable environments such as modern communication networks.
A practical public key cryptosystem provably secure against adaptive chosen ciphertext attack
 CRYPTO '98
, 1998
"... A new public key cryptosystem is proposed and analyzed. The scheme is quite practical, and is provably secure against adaptive chosen ciphertext attack under standard intractability assumptions. There appears to be no previous cryptosystem in the literature that enjoys both of these properties simu ..."
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Cited by 542 (17 self)
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A new public key cryptosystem is proposed and analyzed. The scheme is quite practical, and is provably secure against adaptive chosen ciphertext attack under standard intractability assumptions. There appears to be no previous cryptosystem in the literature that enjoys both of these properties simultaneously.
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 517 (69 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 460 (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.
Authenticated Key Exchange Secure Against Dictionary Attacks
, 2000
"... Passwordbased protocols for authenticated key exchange (AKE) are designed to work despite the use of passwords drawn from a space so small that an adversary might well enumerate, off line, all possible passwords. While several such protocols have been suggested, the underlying theory has been laggi ..."
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Cited by 401 (35 self)
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Passwordbased protocols for authenticated key exchange (AKE) are designed to work despite the use of passwords drawn from a space so small that an adversary might well enumerate, off line, all possible passwords. While several such protocols have been suggested, the underlying theory has been lagging. We begin by defining a model for this problem, one rich enough to deal with password guessing, forward secrecy, server compromise, and loss of session keys. The one model can be used to define various goals. We take AKE (with "implicit" authentication) as the "basic" goal, and we give definitions for it, and for entityauthentication goals as well. Then we prove correctness for the idea at the center of the Encrypted KeyExchange (EKE) protocol of Bellovin and Merritt: we prove security, in an idealcipher model, of the twoflow protocol at the core of EKE.
Analysis of keyexchange protocols and their use for building secure channels
, 2001
"... Abstract. We present a formalism for the analysis of keyexchange protocols that combines previous definitional approaches and results in a definition of security that enjoys some important analytical benefits: (i) any keyexchange protocol that satisfies the security definition can be composed with ..."
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Cited by 332 (20 self)
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Abstract. We present a formalism for the analysis of keyexchange protocols that combines previous definitional approaches and results in a definition of security that enjoys some important analytical benefits: (i) any keyexchange protocol that satisfies the security definition can be composed with symmetric encryption and authentication functions to provide provably secure communication channels (as defined here); and (ii) the definition allows for simple modular proofs of security: one can design and prove security of keyexchange protocols in an idealized model where the communication links are perfectly authenticated, and then translate them using general tools to obtain security in the realistic setting of adversarycontrolled links. We exemplify the usability of our results by applying them to obtain the proof of two classes of keyexchange protocols, DiffieHellman and keytransport, authenticated via symmetric or asymmetric techniques. 1
NonMalleable NonInteractive Zero Knowledge and Adaptive ChosenCiphertext Security
, 1999
"... We introduce the notion of nonmalleable noninteractive zeroknowledge (NIZK) proof systems. We show how to transform any ordinary NIZK proof system into one that has strong nonmalleability properties. We then show that the elegant encryption scheme of Naor and Yung [NY] can be made secure against ..."
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Cited by 187 (18 self)
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We introduce the notion of nonmalleable noninteractive zeroknowledge (NIZK) proof systems. We show how to transform any ordinary NIZK proof system into one that has strong nonmalleability properties. We then show that the elegant encryption scheme of Naor and Yung [NY] can be made secure against the strongest form of chosenciphertext attack by using a nonmalleable NIZK proof instead of a standard NIZK proof. Our encryption scheme is simple to describe and works in the standard cryptographic model under general assumptions. The encryption scheme can be realized assuming the existence of trapdoor permutations. 1 Introduction Modern cryptography provides us with several fundamental tools, from encryption schemes to zeroknowledge proofs. For each of these tools, we have some intuition about what they "should" achieve. But we must be careful to understand the gap between our intuition and what we can actually achieve. Indeed, a major goal of cryptography is to refine our tools to br...
The Elliptic Curve Digital Signature Algorithm (ECDSA)
, 1999
"... The Elliptic Curve Digital Signature Algorithm (ECDSA) is the elliptic curve analogue of the Digital Signature Algorithm (DSA). It was accepted in 1999 as an ANSI standard, and was accepted in 2000 as IEEE and NIST standards. It was also accepted in 1998 as an ISO standard, and is under consideratio ..."
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Cited by 183 (5 self)
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The Elliptic Curve Digital Signature Algorithm (ECDSA) is the elliptic curve analogue of the Digital Signature Algorithm (DSA). It was accepted in 1999 as an ANSI standard, and was accepted in 2000 as IEEE and NIST standards. It was also accepted in 1998 as an ISO standard, and is under consideration for inclusion in some other ISO standards. Unlike the ordinary discrete logarithm problem and the integer factorization problem, no subexponentialtime algorithm is known for the elliptic curve discrete logarithm problem. For this reason, the strengthperkeybit is substantially greater in an algorithm that uses elliptic curves. This paper describes the ANSI X9.62 ECDSA, and discusses related security, implementation, and interoperability issues. Keywords: Signature schemes, elliptic curve cryptography, DSA, ECDSA.
A Model for Asynchronous Reactive Systems and its Application to Secure Message Transmission
, 2000
"... We present the first rigorous model for secure reactive systems in asynchronous networks with a sound cryptographic semantics, supporting abstract specifications and the composition of secure systems. This enables modular proofs of security, which is essential in bridging the gap between the rigorou ..."
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Cited by 176 (20 self)
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We present the first rigorous model for secure reactive systems in asynchronous networks with a sound cryptographic semantics, supporting abstract specifications and the composition of secure systems. This enables modular proofs of security, which is essential in bridging the gap between the rigorous proof techniques of cryptography and toolsupported formal proof techniques. The model follows the general simulatability approach of modern cryptography. A variety of network structures and trust models can be described, such as static and adaptive adversaries. As an example of our specification methodology we provide the first abstract and complete specification for Secure Message Transmission, improving on recent results by Lynch, and verify one concrete implementation. Our proof is based on a general theorem on the security of encryption in a reactive multiuser setting, generalizing a recent result by Bellare et al.
Composition and Integrity Preservation of Secure Reactive Systems
 In Proc. 7th ACM Conference on Computer and Communications Security
, 2000
"... We consider compositional properties of reactive systems that are secure in a cryptographic sense. We follow the wellknown simulatability approach, i.e., the specification is an ideal system and a real system should in some sense simulate it. We recently presented the first detailed general definit ..."
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Cited by 151 (16 self)
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We consider compositional properties of reactive systems that are secure in a cryptographic sense. We follow the wellknown simulatability approach, i.e., the specification is an ideal system and a real system should in some sense simulate it. We recently presented the first detailed general definition of this concept for reactive systems that allows abstraction and enables proofs of efficient reallife systems like secure channels or certified mail. We proce two important properties...