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141
Attributebased encryption for finegrained access control of encrypted data
 In Proc. of ACMCCS’06
, 2006
"... As more sensitive data is shared and stored by thirdparty sites on the Internet, there will be a need to encrypt data stored at these sites. One drawback of encrypting data, is that it can be selectively shared only at a coarsegrained level (i.e., giving another party your private key). We develop ..."
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Cited by 522 (23 self)
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As more sensitive data is shared and stored by thirdparty sites on the Internet, there will be a need to encrypt data stored at these sites. One drawback of encrypting data, is that it can be selectively shared only at a coarsegrained level (i.e., giving another party your private key). We develop a new cryptosystem for finegrained sharing of encrypted data that we call KeyPolicy AttributeBased Encryption (KPABE). In our cryptosystem, ciphertexts are labeled with sets of attributes and private keys are associated with access structures that control which ciphertexts a user is able to decrypt. We demonstrate the applicability of our construction to sharing of auditlog information and broadcast encryption. Our construction supports delegation of private keys which subsumes Hierarchical IdentityBased Encryption (HIBE). E.3 [Data En
Efficient identitybased encryption without random oracles
, 2005
"... We present the first efficient IdentityBased Encryption (IBE) scheme that is fully secure without random oracles. We first present our IBE construction and reduce the security of our scheme to the decisional Bilinear DiffieHellman (BDH) problem. Additionally, we show that our techniques can be use ..."
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Cited by 346 (19 self)
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We present the first efficient IdentityBased Encryption (IBE) scheme that is fully secure without random oracles. We first present our IBE construction and reduce the security of our scheme to the decisional Bilinear DiffieHellman (BDH) problem. Additionally, we show that our techniques can be used to build a new signature scheme that is secure under the computational DiffieHellman assumption without random oracles. 1
Aggregate and Verifiably Encrypted Signatures from Bilinear Maps
, 2002
"... An aggregate signature scheme is a digital signature that supports aggregation: Given n signatures on n distinct messages from n distinct users, it is possible to aggregate all these signatures into a single short signature. This single signature (and the n original messages) will convince the verif ..."
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Cited by 336 (12 self)
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An aggregate signature scheme is a digital signature that supports aggregation: Given n signatures on n distinct messages from n distinct users, it is possible to aggregate all these signatures into a single short signature. This single signature (and the n original messages) will convince the verifier that the n users did indeed sign the n original messages (i.e., user i signed message M i for i = 1; : : : ; n). In this paper we introduce the concept of an aggregate signature scheme, present security models for such signatures, and give several applications for aggregate signatures. We construct an efficient aggregate signature from a recent short signature scheme based on bilinear maps due to Boneh, Lynn, and Shacham. Aggregate signatures are useful for reducing the size of certificate chains (by aggregating all signatures in the chain) and for reducing message size in secure routing protocols such as SBGP. We also show that aggregate signatures give rise to verifiably encrypted signatures. Such signatures enable the verifier to test that a given ciphertext C is the encryption of a signature on a given message M . Verifiably encrypted signatures are used in contractsigning protocols. Finally, we show that similar ideas can be used to extend the short signature scheme to give simple ring signatures.
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 280 (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
Hierarchical identity based encryption with constant size ciphertext
, 2005
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Hierarchical IDBased Cryptography
, 2002
"... We present hierarchical identitybased encryption schemes and signature schemes that have total collusion resistance on an arbitrary number of levels and that have chosen ciphertext security in the random oracle model assuming the difficulty of the Bilinear DiffieHellman problem. ..."
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Cited by 257 (3 self)
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We present hierarchical identitybased encryption schemes and signature schemes that have total collusion resistance on an arbitrary number of levels and that have chosen ciphertext security in the random oracle model assuming the difficulty of the Bilinear DiffieHellman problem.
Efficient SelectiveID Secure IdentityBased Encryption Without Random Oracles
 6. , SECURE IDENTITY BASED ENCRYPTION WITHOUT RANDOM ORACLES., IN FRANKLIN [20
"... We construct two efficient Identity Based Encryption (IBE) systems that are selective identity secure without the random oracle model. Selective identity secure IBE is a slightly weaker security model than the standard security model for IBE. In this model the adversary must commit ahead of time t ..."
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Cited by 221 (8 self)
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We construct two efficient Identity Based Encryption (IBE) systems that are selective identity secure without the random oracle model. Selective identity secure IBE is a slightly weaker security model than the standard security model for IBE. In this model the adversary must commit ahead of time to the identity that it intends to attack, whereas in the standard model the adversary is allowed to choose this identity adaptively. Our first secure IBE system extends to give a selective identity Hierarchical IBE secure without random oracles.
Efficient SelectiveID Secure Identity Based Encryption without Random Oracles
, 2004
"... We construct two efficient Identity Based Encryption (IBE) systems that are selective identity secure without the random oracle model. Selective identity secure IBE is a slightly weaker security model than the standard security model for IBE. In this model the adversary must commit ahead of time to ..."
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Cited by 154 (9 self)
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We construct two efficient Identity Based Encryption (IBE) systems that are selective identity secure without the random oracle model. Selective identity secure IBE is a slightly weaker security model than the standard security model for IBE. In this model the adversary must commit ahead of time to the identity that it intends to attack, whereas in the standard model the adversary is allowed to choose this identity adaptively. Our first secure IBE system extends to give a selective identity Hierarchical IBE secure without random oracles.
Fully Secure Functional Encryption: AttributeBased Encryption and (Hierarchical) Inner Product Encryption
"... In this paper, we present two fully secure functional encryption schemes. Our first result is a fully secure attributebased encryption (ABE) scheme. Previous constructions of ABE were only proven to be selectively secure. We achieve full security by adapting the dual system encryption methodology r ..."
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Cited by 145 (21 self)
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In this paper, we present two fully secure functional encryption schemes. Our first result is a fully secure attributebased encryption (ABE) scheme. Previous constructions of ABE were only proven to be selectively secure. We achieve full security by adapting the dual system encryption methodology recently introduced by Waters and previously leveraged to obtain fully secure IBE and HIBE systems. The primary challenge in applying dual system encryption to ABE is the richer structure of keys and ciphertexts. In an IBE or HIBE system, keys and ciphertexts are both associated with the same type of simple object: identities. In an ABE system, keys and ciphertexts are associated with more complex objects: attributes and access formulas. We use a novel informationtheoretic argument to adapt the dual system encryption methodology to the more complicated structure of ABE systems. We construct our system in composite order bilinear groups, where the order is a product of three primes. We prove the security of our system from three static assumptions. Our ABE scheme supports arbitrary monotone access formulas. Our second result is a fully secure (attributehiding) predicate encryption (PE) scheme
Searchable encryption revisited: Consistency properties, relation to anonymous IBE, and extensions
, 2005
"... We identify and fill some gaps with regard to consistency (the extent to which false positives are produced) for publickey encryption with keyword search (PEKS). We define computational and statistical relaxations of the existing notion of perfect consistency, show that the scheme of [7] is compu ..."
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Cited by 143 (3 self)
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We identify and fill some gaps with regard to consistency (the extent to which false positives are produced) for publickey encryption with keyword search (PEKS). We define computational and statistical relaxations of the existing notion of perfect consistency, show that the scheme of [7] is computationally consistent, and provide a new scheme that is statistically consistent. We also provide a transform of an anonymous IBE scheme to a secure PEKS scheme that, unlike the previous one, guarantees consistency. Finally we suggest three extensions of the basic notions considered here, namely anonymous HIBE, publickey encryption with temporary keyword search, and identitybased encryption