Encrypted search system design for email client-side encryption
US11308224B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 13, 2019 |
| Grant date | Apr 19, 2022 |
| Priority date | — |
| Expiry date | Jun 9, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L63/0428
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method for providing an encrypted search system includes receiving a search query for a keyword that appears in one or more encrypted emails stored on an untrusted storage device and accessing, a count table to obtain a count of unique emails within the emails that include the keyword. The method also includes generating a delegatable pseudorandom function (DPRF) based on the keyword, a private cryptographic key, and the count of unique emails that include the keyword and delegating at least a portion of the DPRF to the untrusted storage device that causes the storage device to evaluate the delegated DPRF, access an encrypted search index associated with the emails, and determine one or more encrypted emails associated with the delegated DPRF based on the encrypted search index. The storage device also returns, to the user device, an identifier for each encrypted email associated with the delegated DPRF.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.