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512
IdentityBased Encryption from the Weil Pairing
, 2001
"... We propose a fully functional identitybased encryption scheme (IBE). The scheme has chosen ciphertext security in the random oracle model assuming an elliptic curve variant of the computational DiffieHellman problem. Our system is based on bilinear maps between groups. The Weil pairing on elliptic ..."
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Cited by 1750 (28 self)
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We propose a fully functional identitybased encryption scheme (IBE). The scheme has chosen ciphertext security in the random oracle model assuming an elliptic curve variant of the computational DiffieHellman problem. Our system is based on bilinear maps between groups. The Weil pairing on elliptic curves is an example of such a map. We give precise definitions for secure identity based encryption schemes and give several applications for such systems.
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.
NonMalleable Cryptography
 SIAM Journal on Computing
, 2000
"... The notion of nonmalleable cryptography, an extension of semantically secure cryptography, is defined. Informally, in the context of encryption the additional requirement is that given the ciphertext it is impossible to generate a different ciphertext so that the respective plaintexts are related. ..."
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Cited by 481 (20 self)
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The notion of nonmalleable cryptography, an extension of semantically secure cryptography, is defined. Informally, in the context of encryption the additional requirement is that given the ciphertext it is impossible to generate a different ciphertext so that the respective plaintexts are related. The same concept makes sense in the contexts of string commitment and zeroknowledge proofs of possession of knowledge. Nonmalleable schemes for each of these three problems are presented. The schemes do not assume a trusted center; a user need not know anything about the number or identity of other system users. Our cryptosystem is the first proven to be secure against a strong type of chosen ciphertext attack proposed by Rackoff and Simon, in which the attacker knows the ciphertext she wishes to break and can query the decryption oracle on any ciphertext other than the target.
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 421 (65 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
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
Chosen Ciphertext Attacks Against Protocols Based on the RSA Encryption Standard PKCS1
, 1998
"... This paper introduces a new adaptive chosen ciphertext attack against certain protocols based on RSA. We show that an RSA privatekey operation can be performed if the attacker has access to an oracle that, for any chosen ciphertext, returns only one bit telling whether the ciphertext corresponds to ..."
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Cited by 288 (1 self)
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This paper introduces a new adaptive chosen ciphertext attack against certain protocols based on RSA. We show that an RSA privatekey operation can be performed if the attacker has access to an oracle that, for any chosen ciphertext, returns only one bit telling whether the ciphertext corresponds to some unknown block of data encrypted using PKCS #1. An example of a protocol susceptible to our attackisSSL V.3.0.
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 283 (23 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 279 (13 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
Revocation and Tracing Schemes for Stateless Receivers
, 2001
"... Abstract. We deal with the problem of a center sending a message to a group of users such that some subset of the users is considered revoked and should not be able to obtain the content of the message. We concentrate on the stateless receiver case, where the users do not (necessarily) update their ..."
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Cited by 250 (5 self)
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Abstract. We deal with the problem of a center sending a message to a group of users such that some subset of the users is considered revoked and should not be able to obtain the content of the message. We concentrate on the stateless receiver case, where the users do not (necessarily) update their state from session to session. We present a framework called the SubsetCover framework, which abstracts a variety of revocation schemes including some previously known ones. We provide sufficient conditions that guarantees the security of a revocation algorithm in this class. We describe two explicit SubsetCover revocation algorithms; these algorithms are very flexible and work for any number of revoked users. The schemes require storage at the receiver of log N and 1 2 log2 N keys respectively (N is the total number of users), and in order to revoke r users the required message lengths are of r log N and 2r keys respectively. We also provide a general traitor tracing mechanism that can be integrated with any SubsetCover revocation scheme that satisfies a “bifurcation property”. This mechanism does not need an a priori bound on the number of traitors and does not expand the message length by much compared to the revocation of the same set of traitors. The main improvements of these methods over previously suggested methods, when adopted to the stateless scenario, are: (1) reducing the message length to O(r) regardless of the coalition size while maintaining a single decryption at the user’s end (2) provide a seamless integration between the revocation and tracing so that the tracing mechanisms does not require any change to the revocation algorithm.
Privacy Preserving Auctions and Mechanism Design
, 1999
"... We suggest an architecture for executing protocols for auctions and, more generally, mechanism design. Our goal is to preserve the privacy of the inputs of the participants (so that no nonessential information about them is divulged, even a posteriori) while maintaining communication and computation ..."
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Cited by 248 (13 self)
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We suggest an architecture for executing protocols for auctions and, more generally, mechanism design. Our goal is to preserve the privacy of the inputs of the participants (so that no nonessential information about them is divulged, even a posteriori) while maintaining communication and computational efficiency. We achieve this goal by adding another party  the auction issuer  that generates the programs for computing the auctions but does not take an active part in the protocol. The auction issuer is not a trusted party, but is assumed not to collude with the auctioneer. In the case of auctions, barring collusion between the auctioneer and the auction issuer, neither party gains any information about the bids, even after the auction is over. Moreover, bidders can verify that the auction was performed correctly. The protocols do not require any communication between the bidders and the auction issuer and the computational efficiency is very reasonable. This architecture can be used to implement any mechanism design where the important factor is the complexity of the decision procedure.