Academy of Mathematics and Systems Science, CAS Colloquia & Seminars
Speaker:
Shuhong Gao, Clemson University
Inviter:
Title:
Efficient Fully Homomorphic Encryption Schemes
Time & Venue:
2018.10.18 15:00 N205
Abstract:
As cloud computing, internet of things (IoT) and blockchain technology become increasingly prevalent, there is an urgent need to protect the privacy of massive volumes of sensitive data collected or stored in distributed computer networks or cloud servers, as many of the networks or servers can be vulnerable to external and internal threats such as malicious hackers or curious insiders. The Holy-Grail of cryptography is to have practical fully homomorphic encryption (FHE) schemes that allow any third party (including cloud servers, hackers, miners or insiders) to perform searching or analytics of an arbitrary function on encrypted data without decryption, while no information on the original data is ever leaked. The breakthrough was made by Gentry in 2009 who discovered the first FHE scheme, and since then many improvements have been made on designing more efficient homomorphic encryption schemes. The main bottlenecks are in bootstrapping and large cipher expansion factor (the size ratio of ciphertexts over messages): the current best FHE schemes compute bootstrapping of one bit operation in 0.013 second and still have a cipher expansion factor of 10,000. In this talk, we present a compact FHE scheme whose bootstrapping speed is slightly slower but whose cipher expansion factor is only 6 under private-key encryption and 20 under public-key encryption, hence practical in term of storage.