Encryption at Rest
Encryption at rest, when used in conjunction with transport encryption and good security policies that protect relevant accounts, passwords, and encryption keys, can help ensure compliance with security and privacy standards, including HIPAA, PCI-DSS, and FERPA.
Encrypted Storage Engine
Available in MongoDB Enterprise only.
Available for the WiredTiger Storage Engine only.
MongoDB Enterprise 3.2 introduces a native encryption option for the WiredTiger storage engine. This feature allows MongoDB to encrypt data files such that only parties with the decryption key can decode and read the data.
Changed in version 4.0
MongoDB Enterprise on Windows no longer supports
cipher is now available only on Linux.
If encryption is enabled, the default encryption mode that MongoDB
Enterprise uses is the
AES256-CBC (or 256-bit Advanced Encryption
Standard in Cipher Block Chaining mode) via OpenSSL. AES-256 uses a
symmetric key; i.e. the same key to encrypt and decrypt text. MongoDB
Enterprise for Linux also supports authenticated encryption
AES256-GCM (or 256-bit Advanced Encryption Standard in
Galois/Counter Mode). FIPS mode encryption is also available.
AES256-GCM and Filesystem Backups
For encrypted storage engines that
AES256-GCM encryption mode,
AES256-GCM requires that every
process use a unique counter block value with the key.
For encrypted storage engine
- Restoring from Hot Backup
- Starting in 4.2, if you restore from files taken via "hot"
backup (i.e. the
mongodis running), MongoDB can detect "dirty" keys on startup and automatically rollover the database key to avoid IV (Initialization Vector) reuse.
- Restoring from Cold Backup
However, if you restore from files taken via "cold" backup (i.e. the
mongodis not running), MongoDB cannot detect "dirty" keys on startup, and reuse of IV voids confidentiality and integrity guarantees.
Starting in 4.2, to avoid the reuse of the keys after restoring from a cold filesystem snapshot, MongoDB adds a new command-line option
--eseDatabaseKeyRollover. When started with the
mongodinstance rolls over the database keys configured with
AES256-GCMcipher and exits.
In general, if using filesystem based backups for MongoDB Enterprise 4.2+, use the "hot" backup feature, if possible.
For MongoDB Enterprise versions 4.0 and earlier, if you use
AES256-GCMencryption mode, do not make copies of your data files or restore from filesystem snapshots ("hot" or "cold").
The data encryption process includes:
Generating a master key.
Generating keys for each database.
Encrypting data with the database keys.
Encrypting the database keys with the master key.
The encryption occurs transparently in the storage layer; i.e. all data files are fully encrypted from a filesystem perspective, and data only exists in an unencrypted state in memory and during transmission.
To encrypt all of MongoDB's network traffic, you can use TLS/SSL
(Transport Layer Security/Secure Sockets Layer). See
mongos for TLS/SSL and
TLS/SSL Configuration for Clients.
Secure management of the encryption keys is critical.
The database keys are internal to the server and are only paged to disk in an encrypted format. MongoDB never pages the master key to disk under any circumstances.
Only the master key is external to the server (i.e. kept separate from the data and the database keys), and requires external management. To manage the master key, MongoDB's encrypted storage engine supports two key management options:
Integration with a third party key management appliance via the Key Management Interoperability Protocol (KMIP). Recommended
Local key management via a keyfile.
To configure MongoDB for encryption and use one of the two key management options, see Configure Encryption.
Encryption and Replication
Encryption is not a part of replication:
Master keys and database keys are not replicated, and
Data is not natively encrypted over the wire.
Although you could reuse the same key for the nodes, MongoDB recommends the use of individual keys for each node as well as the use of transport encryption.
For details, see Rotate Encryption Keys.
Available in MongoDB Enterprise only.
Use KMIP Server to Manage Keys for Encrypting the MongoDB Audit Log
Starting in MongoDB 6.0 Enterprise, you can securely manage the keys for encrypting the MongoDB audit log using an external Key Management Interoperability Protocol (KMIP) server.
KMIP simplifies the management of cryptographic keys and eliminates the use of non-standard key management processes.
To use a KMIP server with audit log encryption, configure these settings and parameters:
For testing audit log encryption, you can also use the
Starting in MongoDB 6.0, if you need to downgrade to an earlier MongoDB
version, you must first disable audit log encryption by removing
auditLog.localAuditKeyFile. Existing encrypted audit logs
remain encrypted, and you can keep any procedures you have developed for
storage and processing of encrypted logs.
For audit log encryption, the audit log destination must be a file. syslog cannot be used as the destination.
Unencrypted Audit Log and Process Log
This section applies if you are not using an external Key Management Interoperability Protocol (KMIP) server to manage keys for encrypting the audit log as shown in the previous section.
The audit log file is not encrypted as a part of MongoDB's encrypted
storage engine. A
mongod running with logging may output potentially sensitive
information to log files as a part of normal operations, depending on
the configured log verbosity.
security.redactClientLogData setting to prevent
potentially sensitive information from entering the
mongod process log.
redactClientLogData reduces detail in the log and
may complicate log diagnostics.
See the log redaction manual entry for more information.
Application Level Encryption
Application Level Encryption provides encryption on a per-field or per-document basis within the application layer.
New in version 4.2: MongoDB 4.2-series drivers provides a client-side field level encryption framework. For more information, see Client-Side Field Level Encryption.
To encrypt full documents, write custom encryption and decryption routines or use a commercial solution.
For a list of MongoDB's certified partners, refer to the Partners List.