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GooglePatent applicationSecurity & privacyInterest 4/10

Google patents method to encrypt search indexes with public keys

Patent drawing
Patent drawing from the official filing.

Google describes a system that creates a searchable index of a user's documents and encrypts it using a random key. That key is then locked with the user's public key so only they can unlock it, allowing secure searches without exposing the raw data.

Why it mattersThis approach helps protect personal data during searches by ensuring the service provider cannot read the content or the keys used to access it.

In the filing’s own words

A method for searchable encryption with a public key includes receiving an operation request from a user device associated with a user requesting that encryption of data associated with the user. The data includes a corpus of documents stored on a remote storage device. The method also includes receiving a public key associated with the user. The public key includes an asymmetric cryptographic public key. The method also includes generating a random data key. The data key includes a symmetric cryptographic key. The method also includes encrypting, using the data key, a search index for the corpus of documents based on keywords within the corpus of documents. The method also includes encrypting, using the public key, the data key and sending the encrypted data key to a user device associated with the user.

What exactly they claim (claim 1)

1. A computer-implemented method executed on data processing hardware that causes the data processing hardware to perform operations comprising: receiving an operation request from a user device associated with a user, the operation request requesting encryption of unencrypted data associated with the user; receiving an asymmetric public key associated with the user; generating a first symmetric cryptographic key and a second symmetric cryptographic key; encrypting a search index for the unencrypted data using the first symmetric cryptographic key; encrypting the unencrypted data using the second symmetric cryptographic key; encrypting the first symmetric cryptographic key and the second symmetric cryptographic key using the asymmetric public key; and discarding the unencrypted data, the first symmetric cryptographic key, and the second symmetric cryptographic key.

Facts

Company
Google (Google LLC)
Official title
ENCRYPTED SEARCH WITH A PUBLIC KEY
Publication number
US20260332396A1
Application number
19718676
Filed
Jun 24, 2026
Published
Oct 22, 2026
Inventors
2
Claims
20

Classified under

H04L 9/0825 Electricity & electronicsG06F 16/9032 Physics & computingG06F 16/90335 Physics & computingG06F 16/93 Physics & computingH04L 9/0631 Electricity & electronicsH04L 9/0637 Electricity & electronics
Read the full filing (official PDF) ↗ Open in the Patent Tracker

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Summaries are simplified from the filing’s own abstract and first claim. A patent filing is not a product announcement.
Patent data and drawings: U.S. Patent and Trademark Office (USPTO). Nebula is not affiliated with or endorsed by the USPTO.