[Resource Topic] 2020/1606: PEGASUS: Bridging Polynomial and Non-polynomial Evaluations in Homomorphic Encryption

Welcome to the resource topic for 2020/1606

Title:
PEGASUS: Bridging Polynomial and Non-polynomial Evaluations in Homomorphic Encryption

Authors: Wen-jie Lu, Zhicong Huang, Cheng Hong, Yiping Ma, Hunter Qu

Abstract:

Homomorphic encryption (HE) is considered as one of the most important primitives for privacy-preserving applications. However, an efficient approach to evaluate both polynomial and non-polynomial functions on encrypted data is still absent, which hinders the deployment of HE to real-life applications. To address this issue, we propose a practical framework PEGASUS. PEGASUS can efficiently switch back and forth between a packed CKKS ciphertext and FHEW ciphertexts without decryption, allowing us to evaluate arithmetic functions efficiently on the CKKS side, and to evaluate look-up tables on FHEW ciphertexts. Our FHEW ! CKKS conversion algorithm is more practical than the existing methods. We improve the computational complexity from linear to sublinear. Moreover, the size of our conversion key is significantly smaller, e.g., reduced from 80 gigabytes to 12 megabytes. We present extensive benchmarks of PEGASUS, including sigmoid/ReLU/min/max/division, sorting and max-pooling. To further demonstrate the capability of PEGASUS, we developed two more applications. The first one is a private decision tree evaluation whose communication cost is about two orders of magnitude smaller than the previous HE-based approaches. The second one is a secure K-means clustering that is able to run on thousands of encrypted samples in minutes that outperforms the best existing system by 14 – 20. To the best of our knowledge, this is the first work that supports practical K-means clustering using HE in a single server setting.

ePrint: https://eprint.iacr.org/2020/1606

See all topics related to this paper.

Feel free to post resources that are related to this paper below.

Example resources include: implementations, explanation materials, talks, slides, links to previous discussions on other websites.

For more information, see the rules for Resource Topics .