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Securely Obfuscating Re-Encryption

Susan Hohenberger, Guy N. Rothblum, Abhi Shelat, Vinod Vaikuntanathan
2010 Journal of Cryptology  
Whereas other positive obfuscation results in the standard model apply to very simple point functions, our obfuscation result applies to the significantly more complicated and widely-used re-encryption  ...  This new definition incorporates more security-aware provisions.  ...  scheme is also secure against adversaries who are given an obfuscated re-encryption circuit.  ... 
doi:10.1007/s00145-010-9077-7 fatcat:tupvzahacjffljm2fus6au42ra

Re-encryption, Functional Re-encryption, and Multi-hop Re-encryption: A Framework for Achieving Obfuscation-Based Security and Instantiations from Lattices [chapter]

Nishanth Chandran, Melissa Chase, Feng-Hao Liu, Ryo Nishimaki, Keita Xagawa
2014 Lecture Notes in Computer Science  
Next, we show how our tools can be used to construct secure obfuscators for the functional re-encryption and multi-hop unidirectional re-encryption primitives.  ...  In one of the first works on obfuscating more complex cryptographic functionalities, Hohenberger et al. [25] showed how to securely obfuscate the re-encryption functionality.  ...  Re-encryption has many applications, ranging from secure distributed file servers, to outsourced filtering of encrypted spam, to the iTunes DRM system. Why secure obfuscation for re-encryption?  ... 
doi:10.1007/978-3-642-54631-0_6 fatcat:ojpmobtmercbzg6q5cgo5isszm

Securely Obfuscating Re-encryption [chapter]

Susan Hohenberger, Guy N. Rothblum, abhi shelat, Vinod Vaikuntanathan
Theory of Cryptography  
Whereas other positive obfuscation results in the standard model apply to very simple point functions, our obfuscation result applies to the significantly more complicated and widely-used re-encryption  ...  This new definition incorporates more security-aware provisions.  ...  scheme is also secure against adversaries who are given an obfuscated re-encryption circuit.  ... 
doi:10.1007/978-3-540-70936-7_13 dblp:conf/tcc/HohenbergerRSV07 fatcat:dwsuncbeone2znc34oqpvfjupu

Obfuscating Re-encryption Algorithm With Flexible and Controllable Multi-Hop on Untrusted Outsourcing Server

Mingwu Zhang, Yan Jiang, Yi Mu, Willy Susilo
2017 IEEE Access  
We design a secure multi-hop re-encryption scheme, and then convert the re-encryption program into an obfuscated version with constant-hiding to ensure no sensitive information be revealed.  ...  We design a secure multi-hop reencryption scheme, and then convert the re-encryption program into an obfuscated version with constanthiding to ensure no sensitive information be revealed.  ...  In order to obtain a secure obfuscator for re-encryption program, we firstly design a semantically secure re-encryption scheme, and give the formal security proof for the scheme.  ... 
doi:10.1109/access.2017.2771335 fatcat:i2berlgkmvfjlf4nuzujyec2ji

Functional Re-encryption and Collusion-Resistant Obfuscation [chapter]

Nishanth Chandran, Melissa Chase, Vinod Vaikuntanathan
2012 Lecture Notes in Computer Science  
We introduce a natural cryptographic functionality called functional re-encryption.  ...  We then provide a construction of a functional re-encryption scheme for any function F with a polynomial-size domain and show that it satisfies this notion of collusionresistant obfuscation.  ...  secure obfuscation of the functional re-encryption program w.r.t.  ... 
doi:10.1007/978-3-642-28914-9_23 fatcat:vsa5brlwnjbgrf3ygme2dw7eky

Efficiently Obfuscating Re-Encryption Program Under DDH Assumption [chapter]

Akshayaram Srinivasan, Chandrasekaran Pandu Rangan
2017 Lecture Notes in Computer Science  
(TCC 2007) constructed a pairing-based obfuscator for a family of circuits implementing the re-encryption functionality under a new notion of obfuscation called as average-case secure obfuscation.  ...  security of our encryption -re-encryption system (in the strengthened model) under the DDH-assumption.  ...  We prove the average case secure obfuscator property of our obfuscator and the security of our encryption -re-encryption sustem system under the standard DDH assumption.  ... 
doi:10.1007/978-3-319-61204-1_14 fatcat:2ya3pq33h5boho6f7k7gv52deu

OUP accepted manuscript

2018 Computer journal  
The traditional security notion of PRE focuses on preventing the proxy with the re-encryption key learning anything about the encrypted messages.  ...  In addition, we also show a negative result: a CPA secure proxy re-encryption scheme with "error-freeness" property cannot be non-transferable.  ...  In the above security definition, we do not provide A with any re-encrypted ciphertext for the following two reasons: (1) A can generate re-encrypted ciphertexts from user i * to user j (j ∈ H), and re-encrypted  ... 
doi:10.1093/comjnl/bxy096 fatcat:uz365fdlvbgkfk7u6dd66ghp5q

Secure Obfuscation for Encrypted Signatures [chapter]

Satoshi Hada
2010 Lecture Notes in Computer Science  
In TCC'07, Hohenberger et al. proposed an obfuscator for a re-encryption functionality, which takes a ciphertext for a message encrypted under Alice's public key and transforms it into a ciphertext for  ...  secure obfuscator for it.  ...  and obfuscator presented in Section 5.4, which are much simpler than my original ones, and Henri Gilbert for helping me to revise the submitted version.  ... 
doi:10.1007/978-3-642-13190-5_5 fatcat:f3eekwswszes3dwrki3y53nowy

Universal Constructions and Robust Combiners for Indistinguishability Obfuscation and Witness Encryption [chapter]

Prabhanjan Ananth, Aayush Jain, Moni Naor, Amit Sahai, Eylon Yogev
2016 Lecture Notes in Computer Science  
For witness encryption, we need only one-way functions secure against polynomial time adversaries.  ...  In a recent paper, Goldwasser and Kalai posed as a challenge finding universal constructions for indistinguishability obfuscation and witness encryption.  ...  Acknowledgements We thank Yuval Ishai for helpful discussions and for bringing to our notice the problem of universal obfuscation.  ... 
doi:10.1007/978-3-662-53008-5_17 fatcat:hodmwzkxl5g47esxgmjuipxzza

Chosen Ciphertext Security via Point Obfuscation [chapter]

Takahiro Matsuda, Goichiro Hanaoka
2014 Lecture Notes in Computer Science  
Finally, we show that a lossy encryption scheme can be constructed from an obfuscator for point functions (point obfuscator) that satisfies re-randomizability and a weak form of composability in the worst-case  ...  This result, combined with our second generic construction and several previous results on point obfuscators and MBPF obfuscators, yields a CCA secure PKE scheme that is constructed solely from a re-randomizable  ...  Lossy Encryption from Re-randomizable Point Obfuscation In this section, we show that a re-randomizable point obfuscator yields a lossy encryption scheme.  ... 
doi:10.1007/978-3-642-54242-8_5 fatcat:yzra67anvfdf7ehxt55eirfotm

Indistinguishability Obfuscation with Non-trivial Efficiency [chapter]

Huijia Lin, Rafael Pass, Karn Seth, Sidharth Telang
2016 Lecture Notes in Computer Science  
It is well known that inefficient indistinguishability obfuscators (iO) with running time poly(|C|, λ) · 2 n , where C is the circuit to be obfuscated, λ is the security parameter, and n is the input length  ...  Such inefficient obfuscators, however, are not useful for applications.  ...  The trojan method in functional encryption: From selective to adaptive security. Technical report, generically. Cryptology ePrint Archive, Report 2014/917, 2014.  ... 
doi:10.1007/978-3-662-49387-8_17 fatcat:vjtkpxqrkzdpreb7pncx73l3j4

On the Relationship between Functional Encryption, Obfuscation, and Fully Homomorphic Encryption [chapter]

Joël Alwen, Manuel Barbosa, Pooya Farshim, Rosario Gennaro, S. Dov Gordon, Stefano Tessaro, David A. Wilson
2013 Lecture Notes in Computer Science  
We conclude the paper by recasting the construction of RFE schemes in the context of obfuscation.  ...  construct an RFE from a (standard) semantically secure FE.  ...  As our final contribution, we explore the problem of obfuscating specific re-encryption functionalities, introducing new notions extending those proposed in earlier works on re-encryption [14, 9] .  ... 
doi:10.1007/978-3-642-45239-0_5 fatcat:gml6vajgqjhevgm6ydofrok6pi

Obfuscation of Probabilistic Circuits and Applications [chapter]

Ran Canetti, Huijia Lin, Stefano Tessaro, Vinod Vaikuntanathan
2015 Lecture Notes in Computer Science  
We define several variants of pIO, using different approaches to formalizing the above security requirement, and study non-trivial relations among them.  ...  For obfuscation, we propose a notion that extends indistinguishability obfuscation to probabilistic circuits: It should be hard to distinguish between the obfuscations of any two circuits whose output  ...  Alternatively, consider the task of obfuscation-based re-encryption: Here we wish to "obfuscate" the program that decrypts a ciphertext using an internal decryption key, and then re-encrypts the obtained  ... 
doi:10.1007/978-3-662-46497-7_19 fatcat:rtwezdv5bbavbc2hru7psjy26a

Public-key encryption with keyword search via obfuscation

Chengyu Hu, Pengtao Liu, Rupeng Yang, Yan Xu
2019 IEEE Access  
INDEX TERMS Public-key encryption with keyword search, obfuscation, keyword guessing attacks, multiple functionalities, multi-user setting. 37394 2169-3536  ...  The scheme supports searching on encrypted data by providing to the cloud server an obfuscated simple "decrypt-then-compare" circuit with the secret key and the queried keyword hardwired in it.  ...  This ciphertext is used in the re-encryption circuit C re−enc which is described in Algorithm 5.  ... 
doi:10.1109/access.2019.2905250 fatcat:ptwhfwvgbfduzo2ktdjzm4gcve

Security of Functionally Obfuscated DSP Core Against Removal Attack Using SHA-512 Based Key Encryption Hardware

Anirban Sengupta, Mahendra Rathor
2019 IEEE Access  
This paper presents a novel security mechanism for protecting functionally obfuscated DSP core against removal attack using low-cost, low-power key encryption hardware.  ...  The proposed methodology using lightweight secure hashing algorithm (SHA-512)-based key encryption custom hardware reconfigures the key-bits (resulting into structural reconfiguration) of the locking logic  ...  These N * 8 bits are the encrypted keys for the 'N' different ILBs. Based on these encrypted key-bits, the ILB gate structure is reconfigured (re-structured).  ... 
doi:10.1109/access.2018.2889224 fatcat:a32wc32qgzgybadiuhi73oycs4
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