Fully homomorphic encryption
US9716590B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 16, 2015 |
| Grant date | Jul 25, 2017 |
| Priority date | — |
| Expiry date | Jun 18, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/08
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In one exemplary embodiment of the invention, a method and computer program include: receiving first and second ciphertexts having first and second data encrypted per an encryption scheme, the encryption scheme has public/secret keys and encryption, decryption, operation and refresh functions, the encryption function encrypts data, the decryption decrypts ciphertext, the operation receives ciphertexts and performs operation(s) on them, the refresh operates to prevent growth of the magnitude of noise for a ciphertext while reducing the modulus of the ciphertext without using the secret key, utilizing a modulus switching technique that involves transforming a first ciphertext c modulo q into a second ciphertext c′ modulo p while preserving correctness, the technique includes scaling by p/q and rounding, p<q; using the operation function(s), performing operation(s) on them to obtain a third ciphertext; and reducing a noise level of the third ciphertext using the refresh function.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.