Home | Resources | Meetups | Conference 2025 | Join the community
Practical q-IND-CPA-D-Secure Approximate Homomorphic Encryption
by Lea Nürnberger - 2024.07.18
Video recording (Youtube) | Slides (Github) | Join the discussion (Discord)
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 speaker
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: https://fheorg.substack.com/
The discord server where you can discuss FHE related topics with the community: https://discord.fhe.org
Make sure to join either (or both) of these to stay informed about future events!