<br />

Cloud Firestore automatically encrypts all data before it is written to disk.
There is no setup or configuration required and no need to modify the way you
access the service. The data is automatically and transparently decrypted when
read by an authorized user.

## Key management

With server-side encryption, you can either let Google manage cryptographic
keys on your behalf or use customer-managed encryption keys (CMEK) to manage
the keys yourself.

By default, Google manages cryptographic keys on your behalf using the same
hardened key management systems that we use for our own encrypted data,
including strict key access controls and auditing. Each
Cloud Firestore object's data and metadata is
[encrypted](https://cloud.google.com/docs/security/encryption/default-encryption) and each encryption key is itself encrypted
with a regularly rotated set of master keys.

For information about managing keys yourself, see
[CMEK for Cloud Firestore](https://firebase.google.com/docs/firestore/enterprise/cmek).

## Client-side encryption

Server-side encryption can be used in combination with client-side encryption.
In client-side encryption, you manage your own encryption keys and encrypt data
before writing it to Cloud Firestore. In this case, your data is
encrypted twice, once with your keys and once with the server-side keys.
| **Warning:** Cloud Firestore does not know if your data has already been encrypted client-side, nor does Cloud Firestore have any knowledge of your client-side encryption keys. If you use client-side encryption, you must securely manage your encryption keys.

To protect your data as it travels over the Internet during read and write
operations, we use Transport Layer Security (TLS). For more information about
the supported TLS versions, see
[Encryption in transit in Google Cloud](https://cloud.google.com/docs/security/encryption-in-transit#user_to_google_front_end_encryption).

## What's next

For more information about encryption at rest for Cloud Firestore and
other Google Cloud products, see
[Encryption at Rest in Google Cloud](https://cloud.google.com/docs/security/encryption/default-encryption).