Method and apparatus with encryption based on error variance in homomorphic encryption
AssigneesSamsung Electronics Co., Ltd., Snu R&Db Foundation, Industry-Academic Cooperation Foundation, Chosun University
InventorsHyungchul Kang, Yongwoo Lee, Young-Sik Kim, Jong-Seon No, Joon-woo Lee
Life of this patent
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Abstract
A processor-implemented encryption method using homomorphic encryption includes: receiving data; generating a ciphertext by encrypting the received data; determining a coefficient of an approximating polynomial for performing a modular reduction on a modulus corresponding to the ciphertext, based on an error between the approximating polynomial and a modular reduction function; and performing bootstrapping on the ciphertext by performing the modular reduction based on the determined coefficient of the approximating polynomial.
Claims18
A processor-implemented encryption method using homomorphic encryption, comprising:
- receiving data;
- generating a ciphertext by encrypting the received data;
- determining a coefficient of an approximating polynomial for performing a modular reduction on a modulus corresponding to the ciphertext, by minimizing a value determined based on a variance of an error between the approximating polynomial and a modular reduction function;
- and
- performing bootstrapping on the ciphertext by performing the modular reduction based on the determined coefficient of the approximating polynomial,
- wherein the determining of the coefficient of the approximating polynomial comprises:
- multiplying a weight-constant vector and a squared L2-norm of a coefficient that is based on a degree of the approximating polynomial;
- and
- determining, as the coefficient of the approximating polynomial, a coefficient that minimizes a value determined by adding a result of the multiplying and the variance.
An encryption apparatus using homomorphic encryption, comprising:
- a receiver configured to receive data;
- and
- a processor configured to:
- generate a ciphertext by encrypting the received data;
- determine a coefficient of an approximating polynomial for performing a modular reduction on a modulus corresponding to the ciphertext, by minimizing a value determined based on a variance of an error between the approximating polynomial and a modular reduction function;
- and
- perform bootstrapping on the ciphertext by performing the modular reduction based on the determined coefficient of the approximating polynomial,
- wherein, for the determining of the coefficient of the approximating polynomial, the processor is configured to:
- multiply a weight-constant vector and a squared L2-norm of a coefficient that is based on a degree of the approximating polynomial;
- and
- determine, as the coefficient of the approximating polynomial, a coefficient that minimizes a value determined by adding a result of the multiplying and the variance.
A processor-implemented encryption method using homomorphic encryption, comprising:
- generating a ciphertext by encrypting data;
- determining, as a coefficient of an approximating polynomial, a coefficient that minimizes a value determined based on a variance of an error between the approximating polynomial and a modular reduction function;
- and
- performing bootstrapping on the ciphertext by performing a modular reduction on a modulus corresponding to the ciphertext, based on the determined coefficient,
- wherein the determined value is determined based on the variance, a weight-constant vector corresponding to the coefficient, and a squared L2-norm of the coefficient.
Dependencies are inferred from the claim text.