A Pairing-based Homomorphic Encryption Scheme for Multi-User Settings

2016 ◽  
Vol 12 (2) ◽  
pp. 72-82 ◽  
Author(s):  
Zhang Wei

A new method is presented to privately outsource computation of different users. As a significant cryptographic primitive in cloud computing, homomorphic encryption (HE) can evaluate on ciphertext directly without decryption, thus avoid information leakage. However, most of the available HE schemes are single-user, which means that they could only evaluate on ciphertexts encrypted by the same public key. Adopting the idea of proxy re-encryption, and focusing on the compatibility of computation, the authors provide a pairing-based multi-user homomorphic encryption scheme. The scheme is a somewhat homomorphic one, which can do infinite additions and one multiplication operation. Security of the scheme is based on subgroup decision problem. The authors give a concrete security model and detailed security analysis.

Cryptography ◽  
2020 ◽  
pp. 295-305
Author(s):  
Zhang Wei

A new method is presented to privately outsource computation of different users. As a significant cryptographic primitive in cloud computing, homomorphic encryption (HE) can evaluate on ciphertext directly without decryption, thus avoid information leakage. However, most of the available HE schemes are single-user, which means that they could only evaluate on ciphertexts encrypted by the same public key. Adopting the idea of proxy re-encryption, and focusing on the compatibility of computation, the authors provide a pairing-based multi-user homomorphic encryption scheme. The scheme is a somewhat homomorphic one, which can do infinite additions and one multiplication operation. Security of the scheme is based on subgroup decision problem. The authors give a concrete security model and detailed security analysis.


2021 ◽  
Vol 18 (2(Suppl.)) ◽  
pp. 0899
Author(s):  
RatnaKumari Challa ◽  
VijayaKumari Gunta

Homomorphic encryption became popular and powerful cryptographic primitive for various cloud computing applications. In the recent decades several developments has been made. Few schemes based on coding theory have been proposed but none of them support unlimited operations with security.   We propose a modified Reed-Muller Code based symmetric key fully homomorphic encryption to improve its security by using message expansion technique. Message expansion with prepended random fixed length string provides one-to-many mapping between message and codeword, thus one-to many mapping between plaintext and ciphertext. The proposed scheme supports both (MOD 2) additive and multiplication operations unlimitedly.   We make an effort to prove the security of the scheme under indistinguishability under chosen-plaintext attack (IND-CPA) through a game-based security proof. The security proof gives a mathematical analysis and its complexity of hardness. Also, it presents security analysis against all the known attacks with respect to the message expansion and homomorphic operations.


IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 49232-49239 ◽  
Author(s):  
Tsu-Yang Wu ◽  
Chien-Ming Chen ◽  
King-Hang Wang ◽  
Jimmy Ming-Tai Wu

2014 ◽  
Vol 23 (03) ◽  
pp. 1450033 ◽  
Author(s):  
MIAOMIAO TIAN ◽  
LIUSHENG HUANG ◽  
WEI YANG

Fuzzy identity-based encryption (FIBE) scheme is a kind of identity-based encryption (IBE) scheme, in which any user's identity is composed by a set of attributes and any ciphertext encrypted under identity ID can be decrypted by using a private key corresponding to identity ID′ if ID′ is close to ID as measured by some metric. Due to the error-tolerance property, FIBE scheme is very useful in real-world applications. However, most FIBE schemes are provable secure only in a weaker security model. In order to eliminate this problem, Ren et al. recently proposed a new FIBE scheme and proved that it is fully chosen-ciphertext secure in the standard model. Unfortunately, in this paper, we will show that their FIBE scheme is even not chosen-plaintext secure.


Technologies ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 21
Author(s):  
Ahmed EL-YAHYAOUI ◽  
Mohamed Dafir ECH-CHERIF EL KETTANI

Performing smart computations in a context of cloud computing and big data is highly appreciated today. It allows customers to fully benefit from cloud computing capacities (such as processing or storage) without losing confidentiality of sensitive data. Fully homomorphic encryption (FHE) is a smart category of encryption schemes that enables working with the data in its encrypted form. It permits us to preserve confidentiality of our sensible data and to benefit from cloud computing capabilities. While FHE is combined with verifiable computation, it offers efficient procedures for outsourcing computations over encrypted data to a remote, but non-trusted, cloud server. The resulting scheme is called Verifiable Fully Homomorphic Encryption (VFHE). Currently, it has been demonstrated by many existing schemes that the theory is feasible but the efficiency needs to be dramatically improved in order to make it usable for real applications. One subtle difficulty is how to efficiently handle the noise. This paper aims to introduce an efficient and symmetric verifiable FHE based on a new mathematic structure that is noise free. In our encryption scheme, the noise is constant and does not depend on homomorphic evaluation of ciphertexts. The homomorphy of our scheme is obtained from simple matrix operations (addition and multiplication). The running time of the multiplication operation of our encryption scheme in a cloud environment has an order of a few milliseconds.


2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Shuangjie Bai ◽  
Geng Yang ◽  
Jingqi Shi ◽  
Guoxiu Liu ◽  
Zhaoe Min

The issue of the privacy-preserving of information has become more prominent, especially regarding the privacy-preserving problem in a cloud environment. Homomorphic encryption can be operated directly on the ciphertext; this encryption provides a new method for privacy-preserving. However, we face a challenge in understanding how to construct a practical fully homomorphic encryption on non-integer data types. This paper proposes a revised floating-point fully homomorphic encryption scheme (FFHE) that achieves the goal of floating-point numbers operation without privacy leakage to unauthorized parties. We encrypt a matrix of plaintext bits as a single ciphertext to reduce the ciphertext expansion ratio and reduce the public key size by encrypting with a quadratic form in three types of public key elements and pseudo-random number generators. Additionally, we make the FFHE scheme more applicable by generalizing the homomorphism of addition and multiplication of floating-point numbers to analytic functions using the Taylor formula. We prove that the FFHE scheme for ciphertext operation may limit an additional loss of accuracy. Specifically, the precision of the ciphertext operation’s result is similar to unencrypted floating-point number computation. Compared to other schemes, our FFHE scheme is more practical for privacy-preserving in the cloud environment with its low ciphertext expansion ratio and public key size, supporting multiple operation types and high precision.


2014 ◽  
Vol 989-994 ◽  
pp. 4326-4331
Author(s):  
Ze Tao Jiang ◽  
Xiao Te Huang

This paper puts forward a more efficient fully homomorphic encryption scheme with a view to improving the oversized public key based on the Dijk’s scheme.Encrypted with a cubic form in the public key elements instead of quadratic form by adopting Gentry’s fully homomorphic techonology.The results show that the public key size reduce from to compared to the Coron’s scheme.The security of the proposed scheme is based on both the approximate GCD problem and the sparse-subset sum problem.


2018 ◽  
Vol 52 ◽  
pp. 543-549
Author(s):  
Jing Yang ◽  
Mingyu Fan ◽  
Guangwei Wang

Author(s):  
S. Nagavalli ◽  
G. Ramachandran

<p>The compressive detecting based information accumulation accomplishes with high exactness in information recuperation from less inspection which is available in sensor nodes. In this manner, the existing methods available in the literature diminish the information gathering cost and delays the existence cycle of WSNs. In this paper, a strong achievable security model for sensor network applications was initially proposed. At that point, a secure data collection conspire was displayed based on compressive detecting, which improves the information protection by the asymmetric semi-homomorphic encryption scheme, and decreases the calculation cost by inadequate compressive grid. In this case, particularly the asymmetric mechanism decreases the trouble of mystery key circulation and administration. The proposed homomorphic encryption permits the in-arrange accumulation in cipher domain, and in this manner improves the security and accomplishes the adjustment in system stack. Further, this paper focuses on estimating various network performances such as the calculation cost and correspondence cost, which remunerates the expanding cost caused by the homomorphic encryption. A real time validation on the proposed encryption scheme using AVISPA was additionally performed and the results are satisfactory.</p>


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