Docs Menu
Docs Home
MongoDB Manual
/ / / /


On this page

  • Overview
  • Client-Side Field Level Encryption
  • Other Security Mechanisms
  • Role-Based Access Control
  • Encryption at Rest
  • Transport Encryption (TLS/SSL)
  • Comparison of Features
  • Scenario
  • Solution
  • Learn More

On this page, you can learn about the security benefits of Client-Side Field Level Encryption (CSFLE), and how CSFLE compares to other security mechanisms supported by MongoDB. You can also view a fictional scenario that demonstrates the value of CSFLE in securing your data.

Client-Side Field Level Encryption (CSFLE) is a feature of MongoDB that enables a client application to encrypt data before transporting it over the network. Sensitive data is transparently encrypted and decrypted by the client and only communicated to and from the server in encrypted form. CSFLE keeps encrypted fields secure in the following scenarios:

  • Direct access to encrypted fields by a database superuser

  • Access to encrypted fields by reading the server's memory

  • Capture of encrypted fields over an insecure network

  • Access to on-disk encrypted fields by reading database or backup files

While all clients have access to the non-sensitive data fields, only appropriately-configured CSFLE clients are able to read and write the encrypted data fields.


Remote Key Management System

When you use CSFLE in production, you must use a remote Key Management System (KMS) to store your encryption key.

To view a step-by-step guide demonstrating how to use a remote KMS with CSFLE, see Tutorials.

To view a list of all supported KMS providers, see KMS Providers.

To learn more about why you should use a remote KMS, see Reasons to Use a Remote Key Management System.

This section describes the following security mechanisms supported by MongoDB and explains their use cases and limitations:

  • Role-Based Access Control

  • Encryption at Rest

  • Transport Encryption (TLS/SSL)

Role-Based Access Control is a security mechanism that allows administrators to grant and restrict collection-level permissions for users. With the appropriate role definition and assignment, this solution prevents accidental disclosure of data and access.

Role-Based Access control cannot protect against the following scenarios:

  • Capture of the data over an insecure network

  • Access to on-disk data by reading database or backup files

  • Access to data by reading the server's memory

  • Direct access to data by a database superuser

To learn more, see Role-Based Access Control.

Encryption at Rest is a mechanism that encrypts database files on disk. This mechanism prevents a person who lacks database credentials, but has access to the computer hosting your database, from viewing your data.

This mechanism does not protect your data against the following scenarios:

  • Capture of the data over an insecure network

  • Access to data by reading the server's memory

  • Direct access to data by a database superuser

To learn more, see Encryption at Rest.

Transport Encryption using TLS/SSL encrypts your data over the network. TLS/SSL protects your data as it travels over an insecure network, but cannot protect your data from a privileged user or as it sits on disk.

To learn more, see Transport Encryption using TLS/SSL

The following diagram lists security features MongoDB supports and the potential security vulnerabilities that they address:

Diagram that describes MongoDB security features and the potential vulnerabilities that they address


Use the Mechanisms Together

To secure a production deployment, use Role-Based Access Control, Encryption at Rest, Transport Encryption, and optionally, the In-Use Encryption security mechanisms together. Please note that you cannot use both CSFLE and Queryable Encryption to encrypt different fields in the same collection.

To learn more about Queryable Encryption, see Queryable Encryption Features.

The following fictional scenario demonstrates the value of Client-Side Field Level Encryption (CSFLE) in securing your application's data, and how CSFLE interacts with the other security mechanism discussed in this guide.

In this scenario, we secure sensitive data on a medical care management system that stores patients' personal information, insurance information, and medical records for a fictional company, MedcoMD. None of the patient data is public, and specific data such as their social security number (SSN, a US government-issued ID number), insurance policy number, and vital sign measurements are particularly sensitive and subject to privacy compliance. It is important for the company and the patient that the data is kept private and secure.

MedcoMD needs this system to satisfy the following use cases:

  • Doctors use the system to access patients' medical records, insurance information, and add new vital sign measurements.

  • Receptionists use the system to verify patients' identities using their contact information.

  • Receptionists can view a patient's insurance policy provider, but not their policy number.

  • Receptionists cannot access a patient's medical records.

MedcoMD is also concerned with the disclosure of sensitive data through any of the following methods:

  • Accidental disclosure of data on a receptionist's publicly-viewable screen.

  • Direct access to the database by a superuser such as a database administrator.

  • Capture of data over an insecure network.

  • Access to data by reading the database server's memory.

  • Access to data by reading database or backup files.

What can MedcoMD do to balance the functionality and access restrictions of their medical care management system?

MedcoMD uses the following security mechanisms to satisfy their use cases and protect against the disclosure of sensitive medical data:

  • Transport Encryption (TLS/SSL) to secure data as it travels over the network.

  • Encryption at Rest to protect against disclosure of data by reading database or backup files.

  • Role-Based Access Control to limit the access of database users to the collections necessary for them to perform their tasks.

  • Encrypting sensitive fields with CSFLE to satisfy the following use cases and constraints:

    • Prevent reading data from server memory as the CSFLE encrypted data is never on the database server in an unencrypted form.

    • Allow receptionists to verify patients' identities and prevent accidental disclosure of sensitive data on a receptionist's publicly viewable screen by providing receptionists with a client that is not CSFLE-enabled.

    • Allow doctors to view sensitive data privately in their offices by providing doctors with a CSFLE-enabled client.

To view a list of security measures you should implement to protect your MongoDB deployment, see the Security Checklist.

To start using CSFLE, see the Quick Start.


Client-Side Field Level Encryption


Installation Requirements