Reducing homomorphic encryption rotations when reshaping a ciphertext
US12425183B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 2024 |
| Grant date | Sep 23, 2025 |
| Priority date | — |
| Expiry date | May 29, 2044 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L9/008
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Reducing homomorphic encryption (HE) rotations is provided. Input of a source tensor of HE ciphertexts is received and a mapping of elements from the source tensor to a target tensor. For each ciphertext, a vector of required rotations is computed according to the mapping plus a list of unique rotations. A first and second list of rotations are generated which have a combined number of rotations less than the list of unique rotations. For each rotation in the first list a ciphertext vector is computed that holds selected elements cyclically rotated by that rotation. For each rotation in the second list a subset of elements is selected from the ciphertext which is summed with ciphertext vectors generated according to the first list. A rotated ciphertext is generated from this sum rotated by the rotation in the second list. Rotated ciphertexts are summed, and the target tensor is output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.