US 12,238,198 B2
Enabling constant plaintext space in bootstrapping in fully homomorphic encryption
Hao Chen, Kirkland, WA (US); and Kyoohyung Han, Seoul (KR)
Assigned to Microsoft Technology Licensing, LLC, Redmond, WA (US)
Filed by Microsoft Technology Licensing, LLC, Redmond, WA (US)
Filed on May 3, 2021, as Appl. No. 17/306,715.
Application 17/306,715 is a continuation of application No. 15/965,006, filed on Apr. 27, 2018, granted, now 11,032,061.
Prior Publication US 2021/0399872 A1, Dec. 23, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. H04L 29/06 (2006.01); H04L 9/00 (2022.01); H04L 9/06 (2006.01)
CPC H04L 9/008 (2013.01) [H04L 9/0631 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A computer-implemented method for data security and accuracy using fully homomorphic encryption, the method comprising:
applying, at processing hardware, an error term to each of a plurality of encoded digits in a first polynomial to obtain a second polynomial;
applying, at the processing hardware, digit extraction to a first batch encryption of the second polynomial resulting in a second batch encryption, the digit extraction including successive application of a lifting polynomial to respective terms of the first batch encryption resulting in a first lifted polynomial and application of a lowest digit extraction polynomial to remove the error term from the lifted first polynomial resulting in the second batch encryption;
performing a homomorphic encryption operation using the second batch encryption; and
providing a result of the homomorphic encryption operation to a component over a communication channel.