US 11,870,889 B2
Method and apparatus with homomorphic encryption
Jong-Seon No, Seoul (KR); Yongwoo Lee, Seoul (KR); and Young-Sik Kim, Gwangju (KR)
Assigned to Samsung Electronics Co., Ltd., Suwon-si (KR); Seoul National University R & DB Foundation, Seoul (KR); and Industry Academic Cooperation Foundation, Chosun University, Gwangju (KR)
Filed by Samsung Electronics Co., Ltd., Suwon-si (KR); Seoul National University R&DB Foundation, Seoul (KR); and Industry Academic Cooperation Foundation, Chosun University, Gwangju (KR)
Filed on Nov. 2, 2021, as Appl. No. 17/516,924.
Claims priority of application No. 10-2021-0024262 (KR), filed on Feb. 23, 2021; and application No. 10-2021-0062640 (KR), filed on May 14, 2021.
Prior Publication US 2022/0271922 A1, Aug. 25, 2022
Int. Cl. H04L 9/08 (2006.01); H04L 9/06 (2006.01); H04L 9/00 (2022.01); G06F 7/76 (2006.01); G06F 17/16 (2006.01); G06F 7/523 (2006.01)
CPC H04L 9/0825 (2013.01) [G06F 7/523 (2013.01); G06F 7/766 (2013.01); G06F 17/16 (2013.01); H04L 9/008 (2013.01); H04L 9/0618 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A processor-implemented method with homomorphic encryption, the method comprising:
receiving a first ciphertext corresponding to a first modulus;
generating a second ciphertext corresponding to a second modulus by performing modulus raising on the first ciphertext; and
performing bootstrapping by encoding the second ciphertext using a commutative property and an associative property of operations included in a rotation operation,
wherein the performing of the bootstrapping comprises:
performing a permutation operation on the second ciphertext; and
performing the bootstrapping by performing a key switching operation based on a result of the permutation operation, and
wherein the performing of the bootstrapping by performing the key switching operation based on the result of the permutation operation comprises:
performing a rescaling operation based on the permutation operation;
performing a decompose operation on a result of the rescaling operation; and
performing a sum of multiplications on a result of the decompose operation.