The ones marked may be different from the article in the profile. Hiding the function in functional encryption d boneh, a raghunathan, g segev advances in cryptology crypto 20, 461478, 20. Privacy preserving ciphertext policy attribute based encryption. There are independent application scenarios of index encapsulation. This remained an open problem until 2001, when two independent lines of research boneh and franklin 4, as well as cocks 6 arrived at solutions to the problem. Semantic security when attacker has few private keys. Newest functionalencryption questions cryptography. From singleinput to multiinput functional encryption in the.
Technical report report 2014550, cryptology eprint archive, 2014. We propose a fully functional identitybased encryption scheme ibe. Motivated by the challenge of hiding the search predicates in publickey searchable encryption, in this paper we introduce a new notion of security, function privacy, for identitybased encryption. Pdf identity based encryption ibe constitutes an alternative cryptographic method to the. An identity based encryption scheme based on quadratic residues. An indistinguishably secure function encryption scheme. Identitybased broadcast encryption for inner product. Besides, the role of the pkg is even more central than that of traditional cas. Hiding the function in functional encryption, 461478, dan boneh, gil segev, ananth raghunathan bib info attribute based encryption for circuits from multilinear maps, 479499, shai halevi, craig gentry, amit sahai, brent waters, sanjam garg bib info, video. In the key encapsulation, we use a key to turn a message plaintext into a ciphertext by symmetric encryption, and then we use public key encryption to turn this key into another ciphertext. Hiding the function in functional encryption, 461478, dan boneh, gil segev, ananth raghunathan bib info attributebased encryption for circuits from multilinear maps, 479499, shai halevi, craig gentry, amit sahai, brent waters, sanjam garg bib info, video. Function private functional encryption in the private key setting 5 in the private key setting.
Hiding the function in functional encryption d boneh, a raghunathan, g segev annual cryptology conference, 461478, 20. In such an identitybased encryption ibe scheme there are four algorithms. Martin abadi, dan boneh, ilya mironov, ananth raghunathan and gil segev messagelocked encryption for lockdependent messages advances in cryptology crypto, 20. Functional encryption fe is a novel paradigm supporting restricted decryption keys for a function f that allow one to learn f x j from the encryptions of messages x j. Based on these, delerablee 2007 describes an identitybased broadcast encryption with constant size ciphertexts and private keys. Deterministic publickey encryption for adaptively chosen plaintext distributions. Motivated by the challenge of hiding the search predicates in publickey searchable encryption, in this paper we introduce a new notion of security, function privacy, for identity based encryption. Function private functional encryption and property preserving encryption. Our transformation preserves the message privacy of the underlying scheme and can be instantiated using a variety of existing schemes. Pdf practical implementation of identity based encryption for. Identitybased encryption from the di ehellman assumption. Hiding the function in functional encryption with dan boneh and gil segev crypto 20 messagelocked encryption for.
Identity based broadcast encryption for inner product. In this section, we define the syntax of identitybased broadcast encryption for inner product ibbeip and its security models. In the publickey setting, known constructions of function private functional encryption fpfe were limited to very restricted classes of functionalities like innerproduct. Our system is based on bilinear maps between groups.
In this section, we define the syntax of identity based broadcast encryption for inner product ibbeip and its security models. Ibbeip is derived from ibbe and ipe, where the output of decryption is the inner product associated with the encrypted message instead of the whole message. Making public key functional encryption function private. Additiona lly, the construction o f identity based sig nature was proposed in the same work, but the construction of identity based encryption ibe was left as an open research prob lem. In both cases, the protection of the master keyprivate key is highly important, as the. Starting with the seminal notion of identitybased encryption sha84, bf03, coc01, this need has recently motivated the cryptographic community to develop a. Functional encryption for randomized functionalities in. We put forward a new notion, function privacy, in identity based encryption and, more generally, in functional encryption. Hiding the function in functional encryption with dan boneh and gil segev crypto 20 messagelocked encryption for lockdependent messages. Secure and scalable data collaboration services in. Identitybased encryption from the weil pairing siam. Idbased encryption, or identitybased encryption ibe, is an important primitive of idbased.
Power of publickey functionprivate functional encryption. Functionprivate functional encryption in the privatekey. This process reveals nontrivial information about f and in some cases may entirely leak the functions description unless additional restrictions are imposed, see 8,9,1 for more details. Rsa function for an identitybased signature ibs scheme, but had yet to. Recall that even for the simpler case of identity based encryption, boneh et al.
We propose a fully functional identity based encryption ibe scheme. Function private functional encryption and property. In this paper we signicantly extend the function privacy framework. We combine public key encryption with symmetric encryption to implement the idea of key encapsulation. Our transformation preserves the message privacy of the underlying scheme, and can be instantiated using a variety of existing schemes.
We present a generic transformation that yields a functionprivate functional encryption scheme, starting with any nonfunctionprivate scheme for a sufficiently rich function class. A random oriented identity based encryption process ssrn papers. Apr 17, 2017 we present a generic transformation that yields a function private functional encryption scheme, starting with any non function private scheme for a sufficiently rich function class. In this paper, we provide a broader view on what can be achieved regarding trapdoor privacy in asymmetric searchable encryption schemes, and bridge the gap between previous definitions, which give limited privacy guarantees in practice against search patterns. Hiding the function in functional encryption dan boneh ananth raghunathany gil segevz abstract we put forward a new notion, function privacy, in identitybased encryption and, more gener ally, in functional encryption. The two volumeset, lncs 8042 and lncs 8043, constitutes the refereed proceedings of the 33rd annual international cryptology conference, crypto 20, held in santa barbara, ca, usa, in august 20. Intuitively, our notion asks that decryption keys reveal essentially. Namely, we construct a scheme where a functional key corresponding to a function f enables a user holding. One of the key insights that we utilize in this work is that functionprivate functional encryption. Improved construction for inner product functional encryption. Secure searches in the cloud association for computing. Identitybased broadcast encryption for inner products. Within our framework we develop an approach for designing functionprivate identitybased encryption schemes, leading to constructions that are based on standard assumptions in bilinear groups.
We construct an efficient nongeneric private key functional encryption fe for innerproduct values with fullhiding security, where confidentiality is assured not only for encrypted data but also for functions associated with secret keys. Fully keyhomomorphic encryption, arithmetic circuit abe and compact garbled circuits. Moreover, its power has not been well investigated. Gil segevs publications school of computer science huji.
We present a generic transformation that yields a function private functional encryption scheme, starting with any non function private scheme for a sufficiently rich function class. Were upgrading the acm dl, and would like your input. Id could be a digest using a secure hashfunction of a meaningful identifier. Hiding the function in functional encryption advances in cryptology crypto, 20. The construction is only proved to be secure against selective adversar. In this paper, we consider a secure identitybased encryption scheme to support a finegrained revocation without key escrow and also present a mediated key agreement protocol based on the same. We put forward a new notion, function privacy in identitybased encryption and, more generally, in functional encryption. Within our framework we develop an approach for designing functionprivate identitybased encryption schemes, leading to constructions that are based on. Function private functional encryption in the private key setting zvika brakerski gil segevy abstract functional encryption supports restricted decryption keys that allow users to learn speci c functions of the encrypted messages. In this work, we first design a function encryption scheme by using key encapsulation. Since this time, identitybased cryptography has been a heavilyresearched topic in the field of cryptography 2. Functionprivatesubspacemembership encryption and its. Efficient asymmetric index encapsulation scheme for.
A new approach to practical functionprivate inner product. Trapdoor privacy in asymmetric searchable encryption schemes. They presented a framework for modeling function privacy, and constructed various functionprivate anonymous identitybased encryption schemes which, in particular, imply publickey keyword. The whole game as a computer program is deployed in. They constructed function private publickey functional encryption schemes for point functions equiva. We put forward a new notion, function privacy in identity based encryption and, more generally, in functional encryption. With identitybased encryption, alice can createchoose a public key for bob. In this paper we significantly extend the function privacy framework. Intuitively, our notion asks that decryption keys reveal essentially no information on their corresponding identities, beyond. Functionprivate functional encryption in the privatekey setting 3 function f by evaluating it on any point m of his choosing by rst encrypting m and then using skf to decrypt fm. With flexible and scalable features for finegrained access control, ciphertext policy attribute based encryption cpabe is widely used as a kind of data protection mechanism in the cloud computing. Generalized identity based and broadcast encryption schemes. Hiding the function in functional encryption dan boneh ananth raghunathany gil segevz abstract we put forward a new notion, function privacy, in identitybased encryption and, more generally, in functional encryption. Within our framework we develop an approach for designing function private identity based encryption schemes, leading to constructions that are based on standard assumptions in bilinear groups.
Finally, we present various applications of functionprivate. Secondly, asymmetric index encapsulation scheme does not imply public key encryption or identity based encryption. Functional encryption for randomized functionalities in the. We construct an efficient nongeneric privatekey functional encryption fe for innerproduct values with fullhiding security, where confidentiality is assured not only for encrypted data but also for functions associated with secret keys. Boneh, raghunathan and segev 8,9 initiated the research on function privacy in the public key setting. Motivated by the early examples of functional encryption schemes for speci c functionalities such as identitybased encryption 30,8,16, extensive research has recently been devoted to the construction of functional encryption schemes for rich and expressive families of functions see, for. The scheme has chosen ciphertext security in the random oracle model assuming a variant of the computational diffiehellman problem. The scheme has chosen ciphertext security in the random oracle model assuming a variant of the computational diffiehellman pr. Hiding the function in functional encryption authors.
In this paper, we consider a secure identity based encryption scheme to support a finegrained revocation without key escrow and also present a mediated key agreement protocol based on the same. We put forward a new notion, function privacy, in identitybased encryption and, more generally, in functional encryption. Hiding the function in functional encryption with dan boneh and gil segev in advances in cryptology. Intuitively, our notion asks that decryption keys reveal essentially no information on their corresponding identities, beyond the absolute minimum necessary.
Additiona lly, the construction o f identitybased sig nature was proposed in the same work, but the construction of identitybased encryption ibe was left as an open research prob lem. Fully, almost tightly secure ibe and dual system groups. Efficient functional encryption for innerproduct values. Functionprivate functional encryption in the privatekey setting zvika brakerski gil segevy abstract functional encryption supports restricted decryption keys that allow users to learn speci c functions of the encrypted messages. In this section, we show several other unrelated applications. Identitybased broadcast encryption for inner products the. Identity based searchable encryption can be replaced by any combination of aie and anonymous identity based encryption.
We propose a fully functional identitybased encryption ibe scheme. They presented a framework for modeling function privacy, and constructed various function private anonymous identity based encryption schemes which, in particular, imply publickey keyword. Functionprivate functional encryption in the privatekey setting. To obtain a corresponding private key, the party authorized to use the identity id. Id based cryptosystems with pairing on elliptic curve pdf. With flexible and scalable features for finegrained access control, ciphertext policy attributebased encryption cpabe is widely used as a kind of data protection mechanism in the cloud computing. In this paper, we consider functional privacy in inner product encryption, i. The authors construct fpfe for general functions and explore its powerful applications, both for general and specific functionalities.
Efficient functional encryption for innerproduct values with. Recall that even for the simpler case of identitybased encryption, boneh et al. From singleinput to multiinput functional encryption in the privatekey setting zvika brakerski ilan komargodskiy gil segevz. Hiding the function in functional encryption with dan boneh and gil segev in advances in cryptology crypto 20 3.
From singleinput to multiinput functional encryption in the private key setting zvika brakerski ilan komargodskiy gil segevz abstract we construct a generalpurpose multiinput functional encryption scheme in the private key setting. Functional encryption is a type of publickey encryption, where the party that has access to a secret key can learn a function from that key, which is used to encrypt and decrypt messages. Functionprivate subspacemembership encryption and its applications dan boneh ananth raghunathany gil segevz abstract boneh, raghunathan, and segev crypto have recently put forward the notion of function privacy and applied it to identitybased encryption, motivated by the need for providing predicate privacy in publickey searchable. Finally, we present various applications of function private.
Dan boneh, shamirs original motivation for identitybased encryption was to simplify certificate management in email systems. Function private subspacemembership encryption and its applications with dan boneh and gil segev asiacrypt 20 function private identity based encryption. The weil pairing on elliptic curves is an example of such a map. Although the vast majority of research on functional en. From singleinput to multiinput functional encryption in. Functionprivate subspacemembership encryption and its applications with dan boneh and gil segev asiacrypt 20 functionprivate identitybased encryption. Our transformation preserves the message privacy of the underlying scheme, and can be. Privacy preserving ciphertext policy attribute based. However, in these identitybased broadcasting encryption schemes, only the broadcast center can encrypt messages, and each authorized user just reads the message. In the publickey setting, known constructions of functionprivate functional encryption fpfe were limited to very restricted classes of functionalities like innerproduct. Newest functionalencryption questions cryptography stack. Functionprivate subspacemembership encryption and its. Functionprivate subspace membership encryption and its applications with dan boneh and gil segev in advances in cryptology asiacrypt 20 2. A natural and practical security requirement for fe is to keep not only messages x 1, x q, but also functions f 1, f q, excluding inevitable information f i x j i, j.
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