056 Practical q-IND-CPA-D-Secure Approximate Homomorphic Encryption w/ Lea Nürnberger

Abstract
At Eurocrypt 2021 Li and Micciancio presented a passive key recovery attack on CKKS, leveraging its approximate nature. They proposed a new security notion for approximate homomorphic encryption schemes: q-IND-CPA-D security. In their initial work they left achieving q-IND-CPA-D security for CKKS as an open problem, but they proposed two approaches: noise flooding and exact CKKS. This work addresses the latter approach: a truncated version of CKKS is proposed, where the bits polluted by the error are rounded off. It is shown that thus it is possible to achieve q-IND-CPA-D security for this truncated CKKS without too much loss in efficiency.
About the speakers
Lea is a third year PhD student at the Norwegian University of Technology and Science (NTNU). Her main research area is Fully Homomorphic Encryption.
Never miss an update
* The newsletter where we post community announcements: fheorg.substac...
* The discord server where you can discuss FHE related topics with the community: discord.fhe.org
Make sure to join either (or both) of these to stay informed about future events!
View all resources related to this meetup on fhe.org/meetup...