US 12,475,118 B2
Database table joining under fully homomorphic encryption
Ramy Masalha, Kafr Qari (IL); Allon Adir, Kiryat Tivon (IL); Hayim Shaul, Kfar Saba (IL); Ehud Aharoni, Kfar Saba (IL); Omri Soceanu, Haifa (IL); and Nir Drucker, Zichron Yaakov (IL)
Assigned to INTERNATIONAL BUSINESS MACHINES CORPORATION, Armonk, NY (US)
Filed by International Business Machines Corporation, Armonk, NY (US)
Filed on Mar. 27, 2024, as Appl. No. 18/618,074.
Prior Publication US 2025/0307242 A1, Oct. 2, 2025
Int. Cl. G06F 16/2453 (2019.01); H04L 9/00 (2022.01)
CPC G06F 16/24537 (2019.01) [H04L 9/008 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A computer-implemented method comprising:
appending, into a concatenated table, a second plurality of records in a second table to a first plurality of records in a first table, wherein the first table and the second table each comprise an identification field storing an identification value, wherein the first plurality of records and the second plurality of records in the second table comprise fully homomorphic encrypted data;
sorting, according to each identification value in the concatenated table, the concatenated table, the sorting resulting in a sorted table;
deriving, using each identification value in the sorted table, an equality mask corresponding to the sorted table;
generating, using the equality mask derived from each identification value in the sorted table, an intersection table, the intersection table comprising a record in the first plurality of records with a first identifier value matching a second identifier value in a record in the second plurality of records;
deriving, from the equality mask, a not-in-intersection mask;
generating, using the not-in-intersection mask derived from the equality mask, a not-in-intersection table, the not-in-intersection table comprising a record in the first plurality of records with a third identification value failing to match any identification value in a record in the second plurality of records; and
adding contents of the intersection table and contents of the not-in-intersection table together, the adding resulting in a join table.