InnoDB supports data encryption for tables
tablespaces. This feature provides at-rest encryption for physical
tablespace data files.
Tablespace encryption uses a two tier encryption key architecture,
consisting of a master encryption key and tablespace keys. When a
table is encrypted, a tablespace key is encrypted and stored in
the tablespace header. When an application or authenticated user
wants to access encrypted tablespace data,
InnoDB uses a master encryption key to decrypt
the tablespace key. The decrypted version of a tablespace key
never changes, but the master encryption key may be changed as
required. This action is referred to as master key
The tablespace encryption feature relies on a keyring plugin for master encryption key management.
All MySQL editions provide a
plugin, which stores keyring data in a file local to the server
MySQL Enterprise Edition offers these additional keyring plugins:
keyring_encrypted_fileplugin, which stores keyring data in an encrypted file local to the server host.
keyring_okvplugin, which includes a KMIP client (KMIP 1.1) that uses a KMIP-compatible product as a back end for keyring storage. Supported KMIP-compatible products include centralized key management solutions such as Oracle Key Vault, Gemalto KeySecure, Thales Vormetric key management server, and Fornetix Key Orchestration.
keyring_awsplugin, which communicates with the Amazon Web Services Key Management Service (AWS KMS) as a back end for key generation and uses a local file for key storage.
keyring_encrypted file plugins are not
intended as regulatory compliance solutions. Security standards
such as PCI, FIPS, and others require use of key management
systems to secure, manage, and protect encryption keys in key
vaults or hardware security modules (HSMs).
A secure and robust encryption key management solution, as supported by the other plugins, is critical for security and for compliance with various security standards. When the tablespace encryption feature uses a centralized key management solution, the feature is referred to as “MySQL Enterprise Transparent Data Encryption (TDE)”.
Tablespace encryption supports the Advanced Encryption Standard (AES) block-based encryption algorithm. It uses Electronic Codebook (ECB) block encryption mode for tablespace key encryption and Cipher Block Chaining (CBC) block encryption mode for data encryption.
For frequently asked questions about the tablespace encryption feature, see Section A.16, “MySQL 5.7 FAQ: InnoDB Tablespace Encryption”.
A keyring plugin must be installed and configured. Keyring plugin installation is performed at startup using the
early-plugin-loadoption. Early loading ensures that the plugin is available prior to initialization of the
InnoDBstorage engine. For keyring plugin installation and configuration instructions, see Section 6.5.4, “The MySQL Keyring”.
Only one keyring plugin should be enabled at a time. Enabling multiple keyring plugins is not supported.Important
Once encrypted tables are created in a MySQL instance, the keyring plugin that was loaded when creating the encrypted tables must continue to be loaded using the
early-plugin-loadoption, prior to
InnoDBinitialization. Failing to do so results in errors on startup and during
mysql> SELECT PLUGIN_NAME, PLUGIN_STATUS FROM INFORMATION_SCHEMA.PLUGINS WHERE PLUGIN_NAME LIKE 'keyring%'; +--------------+---------------+ | PLUGIN_NAME | PLUGIN_STATUS | +--------------+---------------+ | keyring_file | ACTIVE | +--------------+---------------+
innodb_file_per_tableoption must be enabled (the default).
InnoDBtablespace encryption only supports file-per-table tablespaces. Alternatively, you can specify the
TABLESPACE='innodb_file_per_table'option when creating an encrypted table or altering an existing table to enable encryption.
Before using the
InnoDBtablespace encryption feature with production data, ensure that you have taken steps to prevent loss of the master encryption key. If the master encryption key is lost, data stored in encrypted tablespace files is unrecoverable. If you are using the
keyring_encrypted_fileplugin, it is recommended that you create a backup of the keyring data file immediately after creating the first encrypted table and before and after master key rotation. For the
keyring_fileplugin, the keyring data file location is defined by the
keyring_file_dataconfiguration option. For the
keyring_encrypted_fileplugin, the keyring data file location is defined by the
keyring_encrypted_file_dataconfiguration option. If you are using the
keyring_awsplugin, ensure that you have performed the necessary configuration. For instructions, see Section 6.5.4, “The MySQL Keyring”.
To enable encryption for a new
ENCRYPTION option in a
CREATE TABLE statement.
mysql> CREATE TABLE t1 (c1 INT) ENCRYPTION='Y';
To enable encryption for an existing
table, specify the
ENCRYPTION option in an
ALTER TABLE statement.
mysql> ALTER TABLE t1 ENCRYPTION='Y';
To disable encryption for an
mysql> ALTER TABLE t1 ENCRYPTION='N';
Plan appropriately when altering an existing table with the
ALTER TABLE ...
ENCRYPTION operations rebuild the table using
ALGORITHM=INPLACE is not supported.
The master encryption key should be rotated periodically and whenever you suspect that the key may have been compromised.
Master key rotation is an atomic, instance-level operation. Each
time the master encryption key is rotated, all tablespace keys
in the MySQL instance are re-encrypted and saved back to their
respective tablespace headers. As an atomic operation,
re-encryption must succeed for all tablespace keys once a
rotation operation is initiated. If master key rotation is
interrupted by a server failure,
the operation forward on server restart. For more information,
see InnoDB Tablespace Encryption and Recovery.
Rotating the master encryption key only changes the master encryption key and re-encrypts tablespace keys. It does not decrypt or re-encrypt associated tablespace data.
Rotating the master encryption key requires the
To rotate the master encryption key, run:
mysql> ALTER INSTANCE ROTATE INNODB MASTER KEY;
ROTATE INNODB MASTER KEY supports concurrent DML.
However, it cannot be run concurrently with
CREATE TABLE ...
ALTER TABLE ...
ENCRYPTED operations, and locks are taken to prevent
conflicts that could arise from concurrent execution of these
statements. If one of the conflicting statements is running, it
must complete before another can proceed.
If a server failure occurs during master key rotation,
InnoDB continues the operation on server
The keyring plugin must be loaded prior to storage engine
initialization so that the information necessary to decrypt
tablespace data pages can be retrieved from tablespace headers
InnoDB initialization and recovery
activities access tablespace data. (See
InnoDB Tablespace Encryption Prerequisites.)
InnoDB initialization and recovery
begin, the master key rotation operation resumes. Due to the
server failure, some tablespaces keys may already be encrypted
using the new master encryption key.
reads the encryption data from each tablespace header, and if
the data indicates that the tablespace key is encrypted using
the old master encryption key,
retrieves the old key from the keyring and uses it to decrypt
the tablepace key.
InnoDB then re-encrypts
the tablespace key using the new master encryption key and saves
the re-encrypted tablespace key back to the tablespace header.
When an encrypted table is exported,
generates a transfer key that is used to
encrypt the tablespace key. The encrypted tablespace key and
transfer key are stored in a
file. This file together with the encrypted tablespace file is
required to perform an import operation. On import,
InnoDB uses the transfer key to decrypt the
tablespace key in the
file. For related information, see
Section 14.7.6, “Copying File-Per-Table Tablespaces to Another Instance”.
ALTER INSTANCE ROTATE INNODB MASTER KEYstatement is only supported in replication environments where the master and slaves run a version of MySQL that supports the tablespace encryption feature.
ALTER INSTANCE ROTATE INNODB MASTER KEYstatements are written to the binary log for replication on slaves.
ALTER INSTANCE ROTATE INNODB MASTER KEYstatement fails, it is not logged to the binary log and is not replicated on slaves.
Replication of an
ALTER INSTANCE ROTATE INNODB MASTER KEYoperation fails if the keyring plugin is installed on the master but not on the slave.
keyring_fileplugin is installed on both the master and a slave but the slave does not have a keyring data file, the replicated
ALTER INSTANCE ROTATE INNODB MASTER KEYstatement creates the keyring data file on the slave, assuming the keyring file data is not cached in memory.
ALTER INSTANCE ROTATE INNODB MASTER KEYuses keyring file data that is cached in memory, if available.
ENCRYPTION option is specified in a
CREATE TABLE or
ALTER TABLE statement, it is
recorded in the
CREATE_OPTIONS field of
field may be queried to identify encrypted tables in a MySQL
mysql> SELECT TABLE_SCHEMA, TABLE_NAME, CREATE_OPTIONS FROM INFORMATION_SCHEMA.TABLES WHERE CREATE_OPTIONS LIKE '%ENCRYPTION="Y"%'; +--------------+------------+----------------+ | TABLE_SCHEMA | TABLE_NAME | CREATE_OPTIONS | +--------------+------------+----------------+ | test | t1 | ENCRYPTION="Y" | +--------------+------------+----------------+
If the server exits or is stopped during normal operation, it is recommended to restart the server using the same encryption settings that were configured previously.
The first master encryption key is generated when the first new or existing table is encrypted.
Master key rotation re-encrypts tablespaces keys but does not change the tablespace key itself. To change a tablespace key, you must disable and re-enable table encryption using
ALTER TABLE, which is an
ALGORITHM=COPYoperation that rebuilds the table.
If a keyring data file (the file named by the
keyring_encrypted_file_datasystem variable) is empty or missing, the first execution of
ALTER INSTANCE ROTATE INNODB MASTER KEYcreates a master encryption key.
keyring_encrypted_fileplugin does not remove an existing keyring data file.
It is recommended that you not place a keyring data file under the same directory as tablespace data files.
keyring_encrypted_file_datasetting at runtime or when restarting the server can cause previously encrypted tables to become inaccessible, resulting in the loss of data.
Advanced Encryption Standard (AES) is the only supported encryption algorithm.
InnoDBtablespace encryption uses Electronic Codebook (ECB) block encryption mode for tablespace key encryption and Cipher Block Chaining (CBC) block encryption mode for data encryption.
ENCRYPTIONattribute of a table is an
ALGORITHM=INPLACEis not supported.
Tablespace encryption is only supported for tables stored in a file-per-table tablespace. Encryption is not supported for tables stored in other tablespace types including general tablespaces, the system tablespace, undo log tablespaces, and the temporary tablespace.
You cannot move or copy an encrypted table from a file-per-table tablespace to an unsupported tablespace type.
Tablespace encryption only applies to data in the tablespace. Data is not encrypted in the redo log, undo log, or binary log.
It is not permitted to change the storage engine of a table that is encrypted or that was previously encrypted.