Abstract
Attribute-based encryption (ABE) is a good choice for one-to-many communication and fine-grained access control of the encryption data in a cloud environment. Fully homomorphic encryption (FHE) allows cloud servers to make valid operations on encrypted data without decrypting. Attribute-based fully homomorphic encryption (ABFHE) from lattices not only combines the bilateral advantages/facilities of ABE and FHE but also can resist quantum attacks. However, in the most previous ABFHE schemes, the growth of ciphertext size usually depends on the total number of system’s attributes which leads to high communication overhead and long running time of encryption and decryption. In this paper, based on the LWE problem on lattices, we propose an attribute-based fully homomorphic scheme with short ciphertext. More specifically, by classifying the system’s attributes and using the special structure matrix in MP12, we remove the dependency of ciphertext size on system’s attributes ℓ and the ciphertext size is no longer increased with the total number of system’s attributes. In addition, by introducing the function G − 1 in the homomorphic operations, we completely rerandomize the error term in the new ciphertext and have a very tight and simple error analysis using sub-Gaussianity. Besides, performance analysis shows that when ℓ = 2 and n = 284 according to the parameter suggestion given by Micciancio and Dai et al., the size of ciphertext in our scheme is reduced by at least 73.3%, not to mention ℓ > 2 . The larger the ℓ , the more observable of our scheme. The short ciphertext in our construction can not only reduce the communication overhead but also reduce the running time of encryption and decryption. Finally, our scheme is proved to be secure in the standard model.
Highlights
Attribute-based encryption (ABE) [1], being proposed by Sahai and Waters in 2005, associates a user’s identity with a set of attributes
Depending on the relevance of access policy, it can be divided into key-policy ABE (KP-ABE) and ciphertext-policy ABE (CP-ABE) [2]
Lattice-based cryptography has been the focus of research in recent years because it is flexible in construction and resistant to quantum attack
Summary
Attribute-based encryption (ABE) [1], being proposed by Sahai and Waters in 2005, associates a user’s identity with a set of attributes. In 2016, based on the construction of Boneh et al [22], Clear and McGoldrick [23] proposed a fully homomorphic KP-ABE scheme from lattices. In this scheme, it can evaluate unbounded depth circuits but with a bounded input; that is, the number of ciphertext is bounded. Brakerski et al [24] proposed another lattice-based fully homomorphic KPABE scheme by using the gadget matrix G and a function G− 1 which are adopted from [22].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
